Final Exam CHEM 1405

Common types of Nuclear Radiation

- Alpha particles - 4/2 - Beta particles - 0 / -1 - Gamma rays - 0 / 0

Calculate the moles of ammonia present in a 3.587 g sample if the molar mass of ammonia is 17.030 g/mol.

0.2106 The molar mass of a compound is the mass of one of compound. Therefore, if you divide a mass of the compound by its molar mass, you will find how many moles of the compound are present. moles of substance=mass in g x (1 mol of substance / molar mass)

End of Ancient Greek View

1661, Robert Boyle published definitions - Elements could not be broken down into simpler substances - Two or more elements combine to form compound In 1800's, Electrolysis of water separated water into simpler elements: hydrogen and oxygen

Example of Electron config

25Mn 1s2 2s2 2p6 3s2 3p6 4s2 3d5 1s2 2s2 2p6 3s2 3p6 3d5 4s2

A hydrometer is a tool used to measure the ? of a liquid relative to that of ?.

A hydrometer is a tool used to measure the density of a liquid relative to that of water.

Insoluble

A substance that cannot be dissolved by the solvent.

What parts are present in every chemical equation?

At least one reactant At least one product An arrow

Chemical Change

Change in chemical composition New substance is formed Examples - Iron rusting (Iron reacting with oxygen) - Burning wood releases carbon dioxide gas

350.0 mL of gas at 25 oC heated to 85 oC, what is new volume if amount and pressure contstant?

Charles' Law. V1 / T1 = V2 / T2 (Convert the temperature into Kelvin: add 273 to both) 350.0 mL x (358 K / 298 K) = 420 mL

Area and Volume

Derived from length measurements/units Area - length x width - SI unit square meter (m2) Volume -occupied space - length x width x height - SI unit cubic meter (m3) 1 m3 = 1000 L 1 dm3 = 1 L 1 cm3 = 1 mL = 1 cc

Scientific Models

Explain complicated phenomena Tangible items or pictures to represent submicroscopic or invisible processes

Amedeo Avogadro (1776-1856)

Explained law of combining volumes in 1811 Avogadro's hypothesis: At same temperature & pressure, equal volumes of gases contain an equal number of particles

The equilibria studied in the lab procedure include which two reactants?

Fe3+ and [CoCl4]2−

Fraction Remaining

Fraction of radioactive isotopes remaining after a given number of half-lives can be determined. number of half-life cycles (n) = total time / half-life fraction remaining = initial amount x 1 / 2n

Equilibrium Constant for Water, Kw

Kw = [H3O+] x [OH- ] = (1x10-7M) x (1x10-7M) = 1x10^-14 For aqueous solutions: Kw = 1x10^-14

Dilution

Only solvent added number solute particles constant, volume changes Volume increase as Concentration decreases C1V1 = C2V2

Combustion (burning)

Oxygen, O2, required Natural gas, is mostly methane, CH4 - Write and balance equation for combustion of methane CH4 + O2 -> CO2 + H2O

Simple Gas Laws

Relationship between two changing variables when other two variables remain constant. Directly variables change in same direction Inversely variables change in opposite direction.

Chemical Equilibrium

Reversible reaction - forward and reverse reaction occur at same time Reactants -> Products Chemical Equilibrium - forward & reverse reaction occur at same time and same rate -Amount of reactants & products NOT always equal

Dispersion

Weakest of all attractive forces Temporary induced dipole due to uneven distribution of electrons Only attraction between nonpolar molecules

Scientific Theories

Well-tested explanation Best current explanation Makes predictions for further experiments Always Tentative

Determine whether each description corresponds to an endothermic reaction or an exothermic reaction.

The reaction mixture feels cool from the outside: Endothermic Heat is a reactant in the reaction: Endothermic Heat is a product in the reaction: Exothermic The reaction mixture feels warm from the outside: Exothermic

Yield

Theoretical Yield - determined from calculations Actual Yield (Experimental Yield) - actually collected/measured during the experiment Percent Yield - Ratio of actual to theoretical % yield = (actual yield / theoretical yield) x 100

Roentgen

Wilhem Roentgen (1845-1923), German scientist accidently discovered X-rays in 1895 - Studied glow on chemically treated paper from cathode ray - Put hand between rays and paper, saw bones on paper received first physics Nobel prize in 1901

1) A key aspect of a scientific hypothesis is that it must be _____.

a) creative b) unique c) testable d) persuasive e) understandable Correct: c) testable

Many common minerals are based on the tetrahedral SiO4 unit. These are generally known as______.

a. Carbonates b. Silicones c. Silicates d. Oxides e. Silanes Correct: c. Silicates

A student performed a density experiment in triplicate and recorded the data shown. Calculate the average density (in g/mL) for this experiment. Density Trial: 1 2.99 g/mL Trial 2 2.82g/mL Trial 3 2.85g/mL

2.89 Three density values are given. To calculate the average density (in g/mL), sum the values and divide the sum by the number of values. An equation for calculating the average is, avg=n1+n2+n3 / n where n is the number of trials, n1 is density for trial 1, n2 is the density for trial 2, and n3 is the density for trial 3.

Suppose you have 350.0 mL of a 0.650 M sodium hydroxide solution. How many moles of sodium hydroxide are in the solution?

0.228 moles of NaOH The definition of molarity is Molarity=moles of solute / liters of solution Because you know the molarity and volume of the solution, you can calculate the moles of sodium hydroxide, NaOH, solute. First, convert milliliters to liters using the definition of the metric prefix. volume in liters=350.0 mL solution x (1 L / 1000 mL) Then, multiply the volume by the molarity to find moles of NaOH. moles of NaOH=volume in liters x (0.650 mol / 1 L)

3.96 mL is the same volume as ________

0.396 cL

Steps in Problem Solving

1. Identify given quantity and desired unit. 2. Write unit plan. 3. Determine equalities or conversion factors required 4. Set up problem using dimensional analysis. • Arrange conversion factor(s) to cancel preceding unit. • Check that all but answer units cancel. • Perform calculations • Report final answer with correct number significant figures and unit.

How many grams of hydrogen are needed if 7.52 g of nitrogen reacts according to the following reaction? N2 + 3 H2 → 2 NH3

1.63 g H2 28.01 g of lN2 needs 6.048 g of lH2 1 g of lN2 needs 6.048 / 28.01g of lH2 7.52g of lN2 needs (6.048×7.52 g) / 28.01 lg of lH2=1.63 g of lH2

A 50 mL graduated cylinder contains 23.5 mL of water. A 42.12 g piece of solid is added to the graduated cylinder and the new volume is 39.1 mL. Calculate the density of the solid?

2.70 g/mL Density = mass of substance / volume of substance 39.1 mL - 23.5 mL = 15.6 mL 42.12 g / 15.6 mL = 2.70

The number of neutrons in iron-59 is:

33

Avogadro's Number

6.022 x 1023 Number of carbon-12 atoms in 12 grams This also equals 1 mol

In the reaction of magnesium metal with hydrochloric acid, how do you determine when the magnesium metal has reacted completely? Select all that apply. Mg(s)+2H+(aq) →Mg2+(aq)+H2(g)

Gas bubbles are no longer produced. The magnesium metal is gone. The magnesium metal and the hydrochloric acid react to produce hydrogen gas. The magnesium is completely reacted when no more bubbles are formed and the magnesium metal is gone.

"Like Dissolves Like"

Gases mix easily - molecules far apart & little interactions. solids or liquids - attractive forces required for mixing

Other Gas Laws: Gay-Lussac

Gay-Lussac, studied the relationship between temperature and pressure of a gas when volume and amount remained constant. Metal air tank as example. P1 / P2 = T1 / T2

Exothermic Reactions

Heat given to surroundings. Reactants -> Products + Heat

Minerals in Hydrosphere

Hydrosphere: liquid layer Water soluble minerals Sea water Major: NaCl Other minerals: Mg, S, Ca, K, Br,

Polar & Nonpolar Molecules

If all bonds nonpolar - molecule is nonpolar. If more than one polar bond present, shape considered. (Methane) Symmetric molecule nonpolar. (Ammonia) Asymmetric molecule polar.

Ion-Dipole Interactions

Ionic substances dissolve in water through ion-dipole interactions.

Ion Self-Check Quiz

Ions of which element(s) need Roman numeral in name? Silver Tungsten Lithium Bromine Correct: Tungsten What is the ionic charge for each of the following ions? Cadmium ion - Cd2+ Selenide ion - Se2- Nitride ion - N3- Lead(IV) ion - Pb4+ Barium ion - Ba2+

John Dalton

John Dalton (1766-1848), English schoolteacher, attempted to explain these 18th century scientific laws and discovered another Dalton's Atomic Theory (1803): 1. All matter composed of atoms 2. Atoms of a given element are alike but different from atoms of another element 3. Different elements combine in fixed proportions to form compounds 4. Atoms not created nor destroyed during chemical reaction, they rearrange

Electrons Flame Tests

Lithium - Pink Sodium - Yellow Potassium - Purple Calcium - Orange Strontium - Hot Pink

Magnesium reacts with oxygen in the air when ?. Unlike other reactions, you should not ? this reaction.

Magnesium reacts with oxygen in the air when lit with a Bunsen burner. Unlike other reactions, you should not look directly at this reaction.

Which of the following would not be helpful in separation a mixture of sand and salt?

Magnet

Periodic Table

Main-group or representative elements - groups 1A - 8A Column one - Alkali Metals Column two - Alkaline Earth Metals Columns three to twelve - Transition elements / metals. Column seventeen - Halogens Column eighteen - Noble Gases

Before Periodic Table

Many attempts to arrange elements Most successful was periodic table published in 1869 by Dmitri Mendeleev (1834-1907), a Russian chemist. - Model for modern periodic table

Numbers obtained from measurements which require estimations are

Measured numbers

Units of Measurement

Number without units has little meaning. - Think about this • pick a number • add a unit to that number • change the unit - Example: 3 • 3 days • 3 hours • 3 meters • all mean different quantities of measure

Metals and Ores

Ores: minerals from which it is possible and practical to extract their metals. Copper ores: sulfides or carbonates, blue to green in color. Iron ores: oxides, rust in color. Aluminum ores - oxides, gray or white in color. Alloys: mixture of two or more elements, one must be metal. Brass & Bronze - copper alloy Bronze is ~10% tin Steel - iron alloy

Lithosphere: Organic & Inorganic

Organic: Comes from living organisms Composed mostly of C & H plus other elements O, N, P & S Inorganic: Rocks and minerals Minerals Inorganic solids With definite chemical composition

Examples of Element Symbols

Oxygen - O Lithium - Li Copper (from Latin, cuprum) -Cu Iron (from Latin, ferrum) - Fe

Light Spectrum

Pass light through prism White light - continuous spectrum (rainbow) of color Different colors = different wavelengths Blue = shorter wavelenth & higher energy Red = longer wavelength & lower energy

Dipole-Dipole

Polar molecules have dipole attracted by dipole-dipole attractions oppositely charged ends will attract each other

Quartz

Pure silicon dioxide or silica (SiO2) silicate tetrahedron (SiO4) in 3-dim. network Gems - crystals with impurities give colored crystals Quartz gemstones: citrine - yellow Fe3+ amethyst - purple Fe4+

_______________________ is an area of chemistry concerned with the identification of substances.

Qualitative analysis

Mass

Quantity of material - Base SI unit is kilogram (kg) - More commonly used in the laboratory • gram 1000 g = 1 kg • milligram 0.001 g = 1 mg or 1000 mg = 1g Measuring mass - A balance is used to measure

Match each polyatomic ion formula to its name.

SO32− Sulfite ClO4- Perchlorate OH− Hydroxide NO2− Nitrite ClO3− Chlorate SO42− Sulfate

Orbitals

Schrödinger's model: probability of finding electron in a given volume - Orbitals - Electron clouds Different shapes for different types of orbitals

Proust: Law of Definite Proportions

Scientists finding substances composed of more than one element Joseph Louis Proust (1754-1826) stated findings in new scientific law in 1799. Law of Definite Proportions - A compound has same elements in certain definite proportion and no other combinations - Also called law of constant composition Implies compounds have constant properties Basis for chemical formulas

Electron Configuration/Arrangement

Shells and subshells are filled from the lowest energy shell/subshell to highest Electron configuration of nitrogen

Determine the molecular geometry based on the description of bonding and lone pairs of electrons around the central atom.

Three single bonds and one lone pair of electrons: Trigonal pyramidal Three double bonds and no lone pairs of electrons: Trigonal planar Five single bonds and no lone pairs of electrons: Trigonal bipyramidal Two single bonds and two lone pairs of electrons: Bent Two double bonds and no lone pairs of electrons: Linear Six single bonds and no lone pairs of electrons: Octahedral Four single bonds and no lone pairs of electrons: Tetrahedral

To determine a covalent compound formula from a compound name, start by ? for each element in the compound. Then, use the ? to determine the subscripts necessary to ?.

To determine a covalent compound formula from a compound name, start by identifying the symbol for each element in the compound. Then, use the prefixes from the name to determine the subscripts necessary to match the number of each element in the name.

Which test is the confirmatory test for ammonium ion?

Wet red litmus paper and sodium hydroxide solution (it will turn blue)

A SiO4 tetrahedron has a silicon atom in the center and an oxygen atom on each of the four corners of the tetrahedron. Silicate materials can be characterized by the structural arrangement of the SiO4 tetrahedra. Match the types of material to the correct structural arrangements. Only use a choice one time. Not all choices will be used.

pure silicon dioxide with a well-organized, three dimensional structure of SiO4 tetrahedra - quartz fibrous chains of SiO4 tetrahedra - asbestos two-dimensional, sheetlike arrays of SiO4 tetrahedra - mica colored crystals of three dimensional structure of SiO4 tetrahedra - gems amorphorous or irregular, three dimensional structure of SiO4 tetrahedra - glass

Chemical Equations

reactant(s) -> product(s) Substances on left - Reactants - Starting materials - Present before reaction Substances on right - Products - Present after reaction The arrow (→) means "yield(s)" or "react(s) to produce." Two or more reactants/products separated by plus (+) sign Heat might be indicated with a triangle on or below the arrow.

A test tube contains K2S2O3 that has been dissloved in water at 22 oC. Additional K2S2O3 was added to this test tube until no more solid would dissolve. The solution in the test tube is now

saturated

Atoms of an element in a compound lose, gain, or share valence electrons in order to produce a stable, noble gas arrangement of electrons. When nitrogen and chlorine combine to form nitrogen trichloride, will nitrogen lose electrons to chlorine, gain electrons from chlorine, or share electrons with chlorine?

share

Asbestos

silicate tetrahedra in one-dimensional fibrous arrays.

Micas

silicate tetrahedra in two-dimensional sheet-like arrays.

Empirical formula

smallest whole-number ratio of atoms in formula

Which one of these elements is an alkali metal?

sodium

HNO3 completely ionizes in water. HNO3 → H+ + NO3- How would an aqueous solution of HNO3 best be classified?

strong acid

The conversion of ammonium salts to ammonia is achieved by the addition of ______________.

strong bases

What type of reaction is the following equation? 2 Sb + 3 Cl2 → 2 SbCl3

synthesis/combination

The measure of the intensity of heat is called

temperature

Molar Mass Determination Examples

C (Carbon) 12.01 g/mol O2 (Oxygen) 32.00 g/mol CO2 (Carbon Dioxide) 44.01 g/mol Ca3(PO4)2 (Calcium phosphate) 310.20 g/mol

Carbon and oxygen can react to form carbon monoxide (CO) or carbon dioxide (CO2) depending on the amount of oxygen available. This illustrates which law?

a) Law of conservation of mass b) Law of definite proportions c) Law of multiple proportions d) Law of combining elements e) The periodic law Correct: c) Law of multiple proportions

2) Which of the following processes represents a chemical change?

a) Water freezes into ice. b) Water evaporates. c) Butter melts in a hot pan. d) A bicycle left outdoors begins to rust. Correct: d) A bicycle left outdoors begins to rust.

Q.1 Which quantity represents the smallest mass?

a)0.001 kg b)1.0 g c) 100 dg d)10 mg e)100,000 (upside down n) g Correct: d)10 mg

Many metal oxides, such as Na2O, dissolve in water to produce: Na2O + H2O → 2 NaOH

a. Acids b. Bases c. Neutral salts d. Covalent compound Correct: b. Bases

Match the correct behavior of ions toward sulfuric acid, H2SO4.

Carbonate, CO32- colorless, odorless gas (carbon dioxide) evolves Iodide, I- Violet or red-brown vapors of elemental iodine form Chloride, Cl- Colorless, pungent gas, HCl evolves, which turns blue litmus red Sulfate, SO42- No observable reaction

Iron Alloys

Cast Iron (Pig Iron) - Alloying Elements 2-4% C - Strong, Rigid, Brittle Wrought Iron - Alloying Elements Very Low C - Tough, Malleable, Ductile, Easily Welded Stainless Steel - Alloying Elements 12-30% Cr; some Ni - Corrosion Resistance Manganese Steel - Alloying Elements 13% Mn; some C - Hardness; Wear resistance Nickle Steel - Alloying Elements .5-.6% Ni; some C - Strength Molybdenum Steel - Alloying Elements 10-15% Mo; some C - Wear Resistance Tungsten Steel - Alloying Elements 1-20% W; some C - Strength at high temperatures.

Heat

Energy associated with particle motion flows from warmer object to cooler one Units of calorie, Calorie, or joule calorie - amount of heat required to raise temperature of 1g of water by 1oC 1 calorie (cal) = 4.184 J 1 Food Calorie (Cal) = 1 kcal = 1000 cal

Calculate mass of carbon dioxide produced when 10.0 g of carbon reacts with oxygen.

Equation: C + O2 = CO2 10.0 g C x (1 mol C / 12.01 g C) x (1 mol CO2 / 1 mol C) x (44.01 g CO2 / 1 mole CO2) = 36.6 g CO2

Calculate mass of oxygen needed to react with 10.0 g carbon

Equation: C + O2 = CO2 10.0 g C x (1 mol C / 12.01 g C) x (1 mol O2 / 1 mol C) x (32.00 g O2 / 1 mol O2) = 26.6 g O2

Behavior of Radioactivity

Ernest Rutherford (1871-1937) - Named three types of radiation - Proposed experiment to test model of atom

Heat was added to an equilibrium system causing the reaction to shift left towards the reactants. Based on the direction of the shift was the reaction endothermic or exothermic?

Exothermic

Which process is used to separate soluble compounds from insoluble compounds?

Extraction

The amount of space an object occupies is called

volume

Changes in Atmospheric Pressure

weather and altitude altitude increases, atmospheric pressure decreases (inverse) pressure on diver increases as diver descends under water

How many moles of HCl are in 43.9 mL of a 1.25 M HCl solution?

0.0549 Molarity, M, is moles of solute, moles, per liters of solution, V M= moles / V Rearrange the equation to solve for moles and plug in the known values. moles=MV =1.25 M×43.9 mL× (1 L / 1000 mL)

A solution is prepared by dissolving 1.2 g of KOH in water to give 125.0 mL of solution. Determine the molarity of this KOH solution?

0.17 M KOH KOH molar mass = 56.1056 1.2 g x (1 mol / 56.1056 g) = 0.0214 mol 125 / 1000 = 0.125 L 0214 / .125 = 0.0.1712 M aka .17 M

Sugar is easily soluble in water and has a molar mass of 342.30 g/mol. What is the molar concentration of a 235.2 mL aqueous solution prepared with 75.2 g of sugar?

0.934 The definition of molarity is Molarity=moles of solute / liters of solution In this example, the solute is sugar and it was dissolved in water to create the aqueous solution. Start the calculation by converting the given mass in grams to moles using the molar mass. moles of sugar= 75.2 g sugar x (1 mol sugar / 342.30 g sugar) Then, convert the volume of solution from milliliters to liters. volume in liters=235.2 mL solution x (1 L / 1000 mL) Finally, divide the moles of sugar by the volume of solution in liters to calculate the molarity.

List of pH to concentration of H+

1 x 10^-0 - pH 0 1 x 10^-1 - pH 1 1 x 10^-2 - pH 2 1 x 10^-3 - pH 3 1 x 10^-4 - pH 4 1 x 10^-5 - pH 5 1 x 10^-6 - pH 6 1 x 10^-7 - pH 7 1 x 10^-8 - pH 8 1 x 10^-9 - pH 9 1 x 10^-10 - pH 10 1 x 10^-11 - pH 11 1 x 10^-12 - pH 12 1 x 10^-13 - pH 13 1 x 10^-14 - pH 14

How may moles of carbon in 10.0 g C?

10.00 g x 1 mol /12.0 g = 0.833 mol C

Molar mass of C 12.01 g/mol

12.01 g / 1 mol C Mole to mass formula 1 mol C / 12.01 g Mass to mole formula

A 5.0 mg sample of a iron-59 with half-life of 45 days. How much iron-59 remains after 135 days?

135 d / 45 d = 3 d 5.0 mg x 1/2^3 = or 5.0 x 1/2 x 1/2 x 1/2 = .625 = .63 mg

Complete the electron configuration of a calcium atom by selecting the correct orbitals.

1s^2 2s^2 2p^6 3s^2 3p^6 4s^2

Which of the following equations is the correctly balanced equation for this reaction? __ Al + __ Br2 → __ AlBr3

2 Al + 3 Br2 → 2 AlBr3

Molarity as Conversion Factor

2.5 M NaCl 2.5 mol NaCl / 1 L solution or 1 L solution / 2.5 mol NaCl

How many waters are needed to balance this equation? (NH4)2Cr2O7 → N2 + Cr2O3 + __ H2O

4

Fill in the expression for the equilibrium constant Kc for the reaction given.

A+2B⟷2C+DA+2B⟷2C+D Kc=C2D / AB2

Indicate the number of valence electrons for atoms of elements in the following families. Enter the number in the box following the family name. Alkali metals [A] Halogens [B]

Alkali metals [A] - 1 Halogens [B] - 7

Nuclear Symbols for Radiation

Alpha particles - 2p+2n ejected Beta particles - n = p+ + e- e- ejected Gamma rays Positron particles

Isotopes

Atoms of same element have same atomic number BUT differ in number neutrons (differ in mass number) mass number = number protons + neutrons Mass # is NOT on periodic table!

Background Radiation

Background Radiation - Cosmic rays - Natural radioisotopes: Air, Water, Soil & Rocks, Food

Names of Acids/Bases

Bases - use ionic or covalent rules Acids - hydrogen ion not named anion ending changes to the acid name. HBr: Hydrogen + -ide ending anion = hydrobromic acid H3PO4: Hydrogen + -ate ending anion =phosphoric acid HNO2: Hydrogen + -ite ending anion = nitrous acid

Exponential Numbers on devices

Be sure you know how calculator displays scientific notation - Most calculators do not show x 10 for exponential notation. Examples of exponential notation calculator display 6 x 10-6 6-06 6E-06 6-06 1.4 x 104 1.4 09 1.4E09 1.409 Entering scientific notation in mastering chemistry - What symbol represents multiplication instead of letter x? • 1.4*109

What is the radioactive particle released in the following nuclear equation? 239 / 93 Np -> 239 / 94 Np + ?

Beta - 0 / -1

Simple Gas Laws Relations

Boyle's Law: P & V (Changing Variables), Inverse Relationship, T & n (Variables Remaining Constant) P1V1 = P2V2 Charles' Law: V & T (Changing Variables), Direct Relationship, P & n (Variables Remaining Constant), V1 / T1 = V2 /T2 Avogadro's Law: V & n (Changing Variables), Direct Relationship, P & T (Variables Remaining Constant), V1 / n1 = V2 / n2

Which of the following is the correct chemical formula for compound bromine pentafluoride?

BrF5

Why is it important that you not breathe on the baking soda test?

Breath contains CO2 which can cloud the test.

Formula Practice 2

Can you write formulas for these 6 ionic compounds? iron(III) chloride - Fe3- Cl - FeCl3 calcium nitride - Ca2+ N3- - Ca3N2 zinc sulfate - Zn2- So4^2- - ZnSO4 chromium(VI) phosphide - Cr6+ P3- - CrP2 cesium telluride - Cs+ Te2- - Cs2Te cobalt(III) nitrite - Co3+ No2- - Co(NO2)3

Mass Relationships in Reactions

Cannot weigh out moles, only mass C + O2 = CO2 C: 12.01 amu O2: 32 amu CO2: 44amu Balanced equations gives moles while periodic table gives mass.

Some Types of Reactions

Combination (Synthesis) Decomposition (Analysis) Replacement (Displacement) - Single-replacement - Double-replacement Combustion (Burning)

graduated cylinder

Commonly used to measure volume.

What are the substances making up a mixture called?

Components

Concentration

Concentration = amount of solute / amount of solution

Determine the empirical formula for this compound containing 12.8 g Cr and 59g Br.

CrBr3

What is empirical formula for compound with: 44.4 g Cu & 5.5 g O

CuxOy Cu: 44.4 g Cu x (1 mol / 63.55 g/mol) = 0.692 mol Cu O: 5.5 g O x (1 mol / 16.00 g/mol) = 0.344 mol O (Divide by the smallest quantity) 0.692 mol Cu / 0.344 mol O = 2 0.344 mol O / .344 mol O = 1 Answer: Cu2O

Proposed atomic theory in 1803 to explain various laws and made observations leading to the law of multiple proportions.

Dalton

Data from Periodic Table

Each element is represented by a box Atomic number, Z Chemical Symbol Atomic mass (weighted average)

How can a solid dissolved in water be separated from the water?

Evaporation

Examples of Molecular formula and Empirical formula

Glucose has molecular formula C6H12O6 Glucose has empirical formula CH2O

Green and Sustainable Chemistry

Green chemistry uses materials and processes that are intended to prevent or reduce pollution at its source. Sustainable chemistry is designed to meet the needs of the present generation without compromising the needs of future generations.

Which reactant in the following equation is the acid? NaCN + HBr → NaBr + HCN

HBr

Half-life on Calculator

How we might write out the equation to determine the amount remaining if 10.0mg undergoes three half-life cycles. 10.0mg x (½)^3 = or 10.0mg x ½ x ½ x ½ = or 10.0mg x (0.5)^3 = 1.25 mg How to enter on scientific calculator 10.0 x 0.5 y^x 3 = or 10.0 x 0.5^3 =

Ionic Bonding and States of Matter

Ionic bond is strong Ionic compounds are typically solids with very high melting points

SI System Chart

Length - meter3 - m Mass - kilograms - kg Time - second - s Temperature - kelvin - k Amount of substance - mole - mol Electric current - ampere - A Luminous intensity - candela - cd

Which of the following is the correct chemical formula for the compound lithium chlorite ?

LiClO2

Suggestions for Balancing Chemical Equations

LiH + AlCl3 -> LiAlH4 + LiCl 1. Balance elements found once on each side 2. Elements in more than one reactant or more than one product give most trouble common problems are O and H

10.0 mL of acid at unknown concentration requires 19.5 mL of 0.20 M NaOH to be neutralized. What is concentration of this acid?

MaVa = MbVb (.20 M x 0.0195 L) / 0.0100 L = 0.39 M

Suppose 0.0350 g Mg is reacted with 10.00 mL of 6 M HCl to produce aqueous magnesium chloride and hydrogen gas. Mg(s)+2HCl(aq)→MgCl2(aq)+H2(g) What is the limiting reactant in this reaction?

Magnesium metal To determine the limiting reactant, calculate the number of moles of each reactant. mol HCl= VHCl×MHCl =10.00 mL × (1 L / 1000 mL) ×6.00 M =0.060 mol HCl mol Mg=mass g Mg / molar mass g =0.00144 mol Mg The limiting reactant is Mg because there are fewer moles of Mg than HCl.

Ions

Metals lose electrons & form positive ions, cations. Na *-> Na+ + 1e- Nonmetals gain electrons & form negative ions, anions. Change ending to -ide for ion name. Cl *7 + 1e- -> Cl *8

How many grams of Mg(NO3)2 is required to react with 27.3 g AgNO3?

MgCl2 (aq) + 2 AgNO3 (aq) = Mg(NO3)2 (aq) + 2 AgCl (s) How many moles of each: 1 MgCl2: 2 AgNO3: 1 Mg(NO3)2+ 2AgCl 27.3 g x (1 mol AgNO3 / 169.88 g AgNO3) x (1 mol Mg(NO3)2 / 2 mol AgNO3) x (148.33 g Mg (NO3)2 / 1 mol Mg (NO3)2) = 11.92 g Mg(NO3)2

Mixtures are characterized by two fundamental properties: Each of the substances in the mixture retains its ? identity. Mixtures are separable into these components by ? means.

Mixtures are characterized by two fundamental properties: Each of the substances in the mixture retains its chemical identity. Mixtures are separable into these components by physical means.

? are combinations of two or more substances.

Mixtures are combinations of two or more substances.

What is Science?

Modern Science - grew out of natural philosophy - 17th Century scientists began to rely on experimentation - experimental method emerged Accumulation of knowledge based on -observations -laws of nature -tests of assumptions

Molarity (M)

Molar concentration -amount of solute in moles per liter sol'n M = moles of solute / L solution

Significant Figures in Calculations 1

Multiplication and Division - Answer should have no more significant digits than factor with fewest total number of significant figures.

Which of the following is the correct chemical formula for compound dinitrogen trioxide?

N2O3

Name for Isotopes

Name element followed by mass number Mg isotopes: magnesium-24 magnesium-25 magnesium-26

Antacids

Neutralize "excess" stomach acid. Hyperacidity is when stomach secretes too much acid. Antacids often taken to neutralize excess acid and reduce the symptoms of hyperacidity. Excessive use of antacids can lead to an increase in pH of blood, a condition known as alkalosis.

Which of the following is the correct symbol for nickel?

Ni

Scientific Method Chart

Observation reported Observation confirmed by others Hypothesis suggested Experiments designed to test hypothesis Experiments do not support hypothesis Hypothesis rejected (Repeat back to hypothesis suggested) New hypothesis offered New experiments tried Experiments support new hypothesis Experiments repeated and results confirmed Theory formulated Many further experiments and so on.

Ideal Gas Law

PV = nRT No variables remain constant P1V1 / n1T1 = P2V2 / n2T2 P1V1 / n1T1 = R R's Value: P1V1 / n1T1 = (1 atm)(22.4 L) / (1 mole)(273 K) = 0.0821 L x atm / mole x K = R

Percent Composition

Percent mass of each element in compound

Periodic Table & Energy Levels

Periods/Rows - Correspond to energy levels (shells) • Works well for representative/main group Blocks/Column groups - Correspond to different subshells - s and p block: Main group (representative) - d block: transition metals (row # -1) - f block: inner transition metals (row # - 2)

Boyle's Law

Robert Boyle studied pressure & volume of gas when temperature and amount constant. volume varies inversely with pressure PV = constant P1V1= P2V2

Which scientist discovered X-rays?

Roentgen

Which of the following is the correct chemical formula for the compound tin(II) nitride ?

Sn3N2

Effect of Temperature on Solubility

Solids in water: More soluble as temperature increases Gases in water: Less soluble as temperature increases

Enter the correct name for each element in the box next to the given element symbol.

Specified Answer for: Ti - Titanium Specified Answer for: P - Phosphorus Specified Answer for: Li - Lithium Specified Answer for: H - Hydrogen Specified Answer for: Fe - Iron Specified Answer for: Si - Silicon Specified Answer for: Au - Gold Specified Answer for: O - Oxygen

Change in state of matter directly from a solid to a gas.

Sublimation

Common Acids

Sulfuric acid - H2SO4 - Strong Acid Hydrochloric acid - HCl - Strong Acid Phosphoric acid - H3PO4 - Moderate Acid Lactic acid - CH3CHOHCOOH - Weak Acid Acetic acid - CH3COOH - Weak Acid Boric acid - H3BO3 - Very weak Acid Hydrocyanic acid - HCN - Very weak Acid

Half-Life

Time it takes for one-half of radioactive isotopes to decay

Covalent Compound Formula

Write Formula from Name Symbol of first element with subscript for prefix. Symbol of second element with subscript for prefix (no subscript if prefix is mono) dinitrogen tetroxide - N2O4

Covalent Compound Name

Write Name from Formula Prefix for subscript with first element name. Prefix of subscript with second element name and ending changed to -ide. (mono prefix has no subscript) SO3 - Sulfur Trioxide

Predict the products of hydrochloric acid reacting with zinc metal.

ZnCl2 and H2

According to the Arrhenius theory, an acid is any substance that dissolves in water to produce:

a. H3O+ b. OH c. Salts d. Ions Correct Answer: a. H3O+

A solution with a [H3O+] of 1 x 10-8 M would be considered:

a. Very acidic b. Slightly acidic c. Neutral d. Slightly basic e. Very basic Correct: d. Slightly Basic pH = 8

How close a measured value is to the actual value is called

accuracy

Precision and Accuracy

accuracy closeness to "correct" or most probable answer precision how closely individual measurements agree reproducibility of measurements reflected by # significant figures reported

What is the name of this compound in water? HC2H3O2 can also be written CH3COOH

acetic acid

Molecular formula (true chemical formula)

actual number of atoms in formula

A mixture containing at least one metal, having metallic properties, is called a(n)

alloy

The radioactive isotope americium-241 is used in smoke detectors.What type of radiation does americium-241 emit? 231 / 95 Am -> 227 / 93 Np + ?

alpha - 4/2

AMU

atomic mass unit

Practice

atomic number for cobalt? - 27 How many protons in phosphorus atom? - 15 How many electrons in tungsten atom? - 74 mass # of sodium isotope with 12 neutrons? - 11 + 12 = 23 Write isotope symbol for tin with mass number 119.- 50p 50 e- 69 n SN (^119) (50)

Atmospheric pressure is measured using a

barometer

Antacids are

bases

Metal oxides that react with water to form metal hydroxides are called

basic anhydrides

Type of emission when an unstable nucleus converts a neutron to a proton and emits an electron from the nucleus.

beta

Artificial Transmutation

bombard atoms with alpha particles or subatomic particles with high energy to penetrate the nucleus creating a new isotope - alters number of protons in nucleus - changes on element into another - typically creates unstable isotopes may not decay like natural radioisotopes

Which one of these elements is a semi-metal/metalloid?

boron

A 1% v/v bromine solution was prepared by dissolving 3 mL of bromine in 297 mL of trichloroethane. Which substance in this soultion is the solute?

bromine

Which of the following is the correct IUPAC name for the compound Cd(OH)2 ?

cadmium hydroxide

Ionic Compounds

cations and anions held together by attractive forces between opposite charged ions, ionic bonds. Rules to name and write formulas sound pretty simple: - Name cation first, then name the anion, omit word "ion" If you do not know the ions, ionic compound names and formulas will be extremely difficult. If you do know the ions it will still be more tedious and time consuming for ionic compounds than covalent compounds.

The designations s, p, d, f in writing electron arrangements (electron configurations) designate

different electron orbitals within an energy level

The strongest type of attractive forces or interactions between nonpolar molecules of CH4 are

dispersion forces

Forces between Molecules

dispersion forces dipole-dipole interactions hydrogen bonding

Valence Electrons

electrons in outermost shell or energy level # valence electrons = group number (1A-8A) for main-group/representative elements.

A reaction that absorbs 65.3 kcal of energy can be classified as ________. Ca(OH)2 + 65.3 kcal -> CaO + H2O

endothermic

Equilibrium Constant (Keq)

equal to concentration of products at equilibrium divided by concentration of reactants at equilibrium. Keq = [products] / [reactants] Pure solids and pure liquids are not included The concentrations are raised to the coefficients.

A chemical reaction that produces heat (gives heat to the surroundings) is considered

exothermic

Separation of a solid from an liquid by carefully pouring mixture through a pourous material such as paper is called

filtration

Chemical Bonds

forces holding atoms together in molecules & ions in crystals

The reaction of silver nitrate and chloride ions results in the ______________.

formation of white insoluble silver chloride precipitate

Change in state from a liquid to a solid is called

freezing

How many electrons does the element phosphorus gain/lose to form a phosphide ion?

gain 3

Breaking and forming bonds during reactions involves energy changes. The overall energy change as reactants become products is called

heat of reaction

The water, above and below the surface, of the Earth is called the

hydrosphere

A tentative "guess" to explain an observation that can be tested is called a(n)

hypothesis

Water is a good solvent for dissolving many inorganic salts. If water is a polar covalent substance and salts are ionic, what intermolecular attractions allow water to interact with ionic compounds?

ion-dipole

Transfer or exchange of electrons from one atom to another forms a(n)

ionic bond

What type of bond between a Pt atom and a Cl atom does the compound PtCl4 possess?

ionic bond

Learn these SI Prefixes

kilo k 1000 10^3 deci d 0.1 10^-1 centi c 0.01 10^-2 milli m 0.001 10^-3 micro (upside down n) 0.000001 10^-6 (upside down n) may appear as mc for prescriptions or in nutrition

Matter is neither created nor destroyed during a chemical reaction. (The total mass of the reactants is equal to the total mass of the products.)

law of conservation of matter

Calcium and chlorine combine to form calcium chloride which always has the formula CaCl2 which illustrates the

law of definite proportions

Carbon and oxygen combine to form carbon dioxide which always has the formula CO2; however, carbon and oxygen can also form carbon monoxide which always has the formula CO. This is an illustration of the

law of multiple proportions

How many electrons does the element magnesium gain/lose to form a magnesium ion?

lose 2

What is the pH of a solution with [H3O+] = 1x10^-3 M

pH = - (log 1x10^-3 M) = - ( -3.0 ) = 3.0

pH Scale

pH = - log [H3O+ ] neutral solution, [H3O+ ] = 1x10^-7M, pH = 7 acidic solution, [H3O+ ] > 1x10^-7M, pH < 7 below 7 basic solution, [H3O+ ]< 1x10^-7M, pH > 7 above 7

Comparison of [H3O+] and pH

pH = - log [H3O+] pH = - (log 1x10-x M) = - ( -X.0 ) = X.0

What is the [H3O+] of aqueous solution with pH = 9.0

pH = -log [H3O+] 9.0 = -log 1x10^-x antilog (-9.0) = 1x10^-9 M

Would a solution that has a hydrogen ion (or hydronium ion) concentration of 1x10-4 M be acidic, basic or neutral?

pH = 4; acidic

Covalent Formula Practice

phosphorus pentachloride - PCl5 nitrogen triiodide - NI3 diselenium octoxide - Se2O8

Which of the following is the correct IUPAC name for compound PI3 ?

phosphorus triiodide

Shape, color, state of matter, melting point, and density are _ _ of a substance.

physical properties

Is this bent molecule polar or nonpolar? Cl2O

polar

What type of bond between S-F does the compound SF6 possess?

polar covalent bond

What is the radioactive particle released in the following nuclear equation?

positron

A substance in which state of matter, generally has stronger intermolecular attractive forces between molecules?

solid

Formula Mass

the sum of the average atomic masses of all the atoms represented in the formula of any molecule, formula unit, or ion Example: C (Carbon) 12.01 amu O2 (Oxygen) 32.00 amu CO2 (Carbon Dioxide) 44.01 amu

Which of the following is the correct IUPAC name for compound Si3Br8 ?

trisilicon octabromide

How many significant figures/digits in the measurement 0.030g?

two

The term atom comes from the Greek word atomos, which means "_____."

very small cannot be seen cannot be cut basis reactive Correct: cannot be cut

Attractive Forces and States of Matter

Solids: Strongest Liquids: Weaker Gas: None (too far apart)

Potassium carbonate contains what % O?

% O = (48.00 g/mol / 138.21 g/mol) x 100 = 34.73% O

States in a Chemical Reaction

(s) solid (l) liquid (g) gas (aq) aqueous = dissolved in water NaCl(s) NaCl(aq) H2O(l) H2O(g)

Ionizing Radiation

- High energy radiation that removes electrons from atoms or molecules creating ions and sometimes free radicals - Nuclear Radiation - X-Rays

Electronegativity

- ability of atom to attract electrons F highest, metals have low & nonmetals have high

Elements & Periodic Table

1776 - ~24 elements known 1830 - ~55 elements and their masses were known Many attempts to arrange elements page 52 Most successful was periodic table published in 1869 by Dmitri Mendeleev (1834-1907), a Russian chemist. - Model for modern periodic table

Determine whether each equation is balanced as written.

2HCl+Mg(OH)2⟶2H2O+MgCl22HCl+Mg(OH)X2⟶2HX2O+MgClX2: Balanced H2+O2⟶2H2OHX2+OX2⟶2HX2O: Not balanced Mg+H2SO4⟶MgSO4+H2Mg+HX2SOX4⟶MgSOX4+HX2: Balanced AgNO3+NaCl⟶NaNO3+AgClAgNOX3+NaCl⟶NaNOX3+AgCl: Balanced CH4+O2⟶CO2+H2OCHX4+OX2⟶COX2+HX2O: Not balanced C6H12O6+O2⟶6CO2+6H2OCX6HX12OX6+OX2⟶6COX2+6HX2O: Not balanced

Balancing Equations Practice

4Fe + 3O2 -> 2Fe2O3 2KIO3 -> 2KI + 3O2 Cl2+ 2KI -> 2KCl + I2

Suppose you are measuring the mass of a solid sample on a balance using a weigh boat. You record the data in a table. Mass of weigh boat2.626 g Mass of weigh boat and sample 8.996 g What is the mass of the solid sample (in g)?

6.370 grams The mass of the sample is the difference between the second mass, which includes both the sample and the weigh boat, and the first mass, which is just the weigh boat. Mass of weigh boat and sample−Mass of weigh boat=Mass of sample If you cannot use the Tare function on a balance, make sure to record the mass of the weigh boat before adding the sample so that this calculation is possible.

Use the ideal gas law to calculate the volume in liters occupied by 0.25 mol of oxygen gas at 0.95 atm pressure and at 315 K. (Express answer to one decimal place and do not enter units.) R= 0.0821 L*atm (K*mol)

6.8 PV=nRT .95 x ? = .25x .0821 x 315 .25 x .0821 x 315 / .95

Chemistry - a Central Science

A Chemistry course is required for most science majors.

Which combination of substances is most likely to form a solution?

A polar molecule in a polar solvent

Who described acids as substances that donate protons (hydrogen ions) and bases as substances that accept protons (hydrogen ions)?

Bronsted & Lowry

States of Matter

A solid has a definite shape and volume. A liquid has a definite volume, but has no definite shape. A gas has neither definite volume nor definite shape.

Identify each described physical separation technique.

A solvent is added to dissolve only one mixture component and then the liquids are separated: Extraction A solid is caught on paper or a membrane while the liquid passes through: Filtration A solid mixture is heated. One component transitions directly between solid and gas: Sublimation A liquid is carefully poured out, leaving the solid behind in the container: Decantation

Scientific Laws 2

Antoine Laurent Lavoisier, 18th century scientist - Father of modern chemistry - First to use systematic names for elements - Carried out quantitative experiments • weighed starting materials and products of reactions • See decomposition of mercuric oxide example below

Atoms: The Greek Idea

Aristotle (about 384-322 B.C.E.) described matter as continuous. - Aristotle's view prevailed for over 2000 years - Greeks viewed matter as four basic elements Leucippus, Greek philosopher, and his pupil, Democritus(ca 460-370 B.C.E.) postulated tiny particles that could not be subdivided - Democritus called indivisible particles atomos

An unknown solution was tested with universal indicator. Use the provided universal indicator pH chart to determine if this solution is acidic, basic or neutral. See results below. This solution is a(n) ? (It's blue)

Base

Which type of substances have the following properties: turns red litmus paper blue, bitter taste, feels slippery, and is found in oven cleaners and bleach?

Base

Percent Concentration

Both solute & solvent liquids - percent by volume Percent by volume = (volume of solute / volume of solution) x 100 Percent by mass common for commercial solutions Percent by mass = (mass of solute / mass of solution) x 100 35.0%m/m HCl means 35.0 g HCl for every 100.0 g solution Note differences between mass percent, percent by volume, and molarity - Require different amounts of solute - 10% HCl solution is considerably different than 10 M HCl

Modified Silicates

Ceramics: Examples: pottery, bricks, tile Inorganic materials heated until particles partially melt and fuse together. Ceramic composites: Mixture of ceramic with plastic or metal Cement: Inorganic materials mixed with water that dry into hard stone-like material - concrete.

A.3 Unit Conversions

Converting given quantity and unit to an equal quantity with a new unit requires a conversion factor. Sometimes two or more conversion factors are required. Conversion Factor - an equality written as fraction Two conversion factors can be written from any equality. See Table A.1 & A.2 for some conversion factors 5280 ft = 1 mile 5280 ft / 1 mile 1 mile / 5280 ft

Covalent Bonding Electron Dot Structures

Diatomic elements: H2 , N2 , O2 , F2 , Cl2 , Br2 , I2 H:H Covalent bond

Henry's Law

Solubility of gas directly related to vapor pressure

Strengths of Acids & Bases

Strong acids or bases ionize completely in water HCl + H2O = H3O+ + Cl- NaOh (H2O) = Na+ + OH- Weak acids or bases ionize slightly in water HF + H2O = H3O+ + F- NH3 + H2O = NH4+ + OH-

Which component of the kinetic molecular theory of gas behavior best explains why a gas can be compressed?

The particles are small and far apart.

he separation of the components of a mixture is based upon the fact that each component has different ? properties. The components of a mixture are separated based on their ? properties.

The separation of the components of a mixture is based upon the fact that each component has different physical properties. The components of a mixture are separated based on their physical properties.

Ionic Charges & Periodic Table

Transition metals, inner transition metals, and metals in Groups 4A-6A charges cannot be predicted by periodic table

Metals with Variable Charge

Transition, inner transition, and metals in Groups 4A-6A Roman numeral in parentheses after name = + ionic charge Nickel(II) ion Ni 2+ Tin(IV) ion Sn 4+ Alkali metals, Alkaline earth metals, Al, Zn, Cd, & Ag DO NOT use Roman numerals to identify charge!

Covalent Compound Naming Prefixes

Two different nonmetals share electrons to form covalent compounds. Memorize: ammonia NH3 water H2O Prefixes for Subscripts Used in Naming Covalent Compounds 1 Mono 2 Di 3 Tri 4 Tetra 5 Penta 6 Hexa 7 Hepta 8 Octa 9 Nona 10 Deca Drop -a or -o from end of prefix in front of oxygen or oxide

The composition of homogeneous mixtures is ______________.

Uniform

Identify the components of the ionic formula based on the name strontium phosphide.

What is the symbol for the element that forms the positive cation? - Sr What is the symbol for the element that forms the negative anion? - P What is the subscript on the cation in the neutral formula? - 3 What is the subscript on the anion in the neutral formula? - 2

When a vinegar and oil salad dressing separates into two layers, the oil floats on top of the vinegar. The density of the oil ? the density of the vinegar.

When a vinegar and oil salad dressing separates into two layers, the oil floats on top of the vinegar. The density of the oil is less than the density of the vinegar.

Whereas ? substances have ? compositions, the composition of ? can vary.

Whereas pure substances have fixed compositions, the composition of mixtures can vary.

Practice Conversion Problems

1) Mass in kilograms of a 155 lb person. equalities: 1 lb = .454 kg or 1 kg = 2.20 lb 155 lb x (.454 kg / 1 lb) = 70.4 kg 155 lb x (1 kg / 2.20 lb) = 70.5 kg 2) Convert 729.9 ft to kilometers. equalities: 5280 ft = 1 mile or 1 mile = 1.61 km ft -> yd -> m -> km 729.9 ft x (1 yd / 3 ft) x (.914 m / 1 yd) x (1 km / 1000 m) =0.222 km. 3) Calculate volume of 125 g of infant formula, which has the density of 1.11 g/mL. equalities: 1.11 g = 1 mL 125 g x (1 mL / 1.11 g)= 113 mL 4) Safe does of anesthetic is 12 mg/kg body wt. Determine safe dose for a 155 lb patient. equalities: 1 lb = .454 kg or 12 mg anesthetic = 1 kg body wt 155 lb x (.454 kg / 1 lb) x (12 mg anesthetic / 1 kg) = 844.44 mg

To convert between units, you need to know the relationship between units. For example, one mile equals 5280 feet. This relationship can now be used as a conversion factor, set up as required by the question. For each conversion, choose the correct arrangement of the conversion factor and complete the calculation.

1. Convert 7860 feet to miles 7860 feet×( 1 mile / 5280 ft ) 2. Convert 0.565 miles to feet 0.565 miles×( 5280 ft / 1 mile )

Energy & Equilibrium Practice handout

1. Is this reaction exothermic or endothermic? HCl + NaOH -> H2O + NaCl + heat (exothermic) 2. Upon addition of H+ to HC2H3O2 ⇄ H+ + C2H3O2 - which direction will the reaction shift? Left 3. Upon adding Cl- to Co(H2O)6 2+ + 4 Cl- ⇄ CoCl4 2- + 6 H2O which direction will the reaction shift? Right 4. If remove water from Co(H2O)6 2+ + 4 Cl- ⇄ CoCl4 2- + 6 H2O which direction will the reaction shift? Right 5. Upon addition of heat to 2 SO3 + 47 kcal ⇄ 2 SO2 + O2 which direction will the reaction shift? Right (endothermic)

Concentration practice

1. Molarity of solution containing 8.5 g MgCl2 in 2.5L? (8.5 g MgCl2 / 2.5 L) x (1 mol / 95.21g MgCl2) = .036 M MgCl2 2. Mass of AgNO3 to prepare 2.5 L of 0.10 M solution? 2.5 L x ( .10 mol AgNO3 / 1 L) x (169.9 g AgNO3 / 1 mol AgNO3) = 42 g AgNO3 3. Volume to prepare 1.5 M solution containing 15.0 g NaCl? 15.0 g NaCl x (1 mol / 58.44 g NaCl) x (1 L / 1.5 mol NaCl) = .17 L NaCl 4. New concentration of solution prepared by diluting 350.0 mL of 1.5 M KCl to 750.0 mL? C1V1 = C2V2 (1.5 M x 350.0 mL) / 750.0 mL = .70 M

Perform the calculation, rounding your answer to the proper number of significant figures. 0.517 x 5.28 x 3.7 =

10 The mathematical operation in the question is multiplication so follow the significant figure rules for multiplication/division, which look at the number of significant figures in each number. The number 3.7 has the fewest significant figures, so the answer can have only two significant figures. When performing the calculation, the answer appears as 10.100112 but you should round it to 10. or 1.0x101, in scientific notation.

Match each description to the correct term.

a liquid consisting of one substance dissolved in another: solution a liquid that dissolves another substance: solvent a value used to describe the amount of one substance dissolved in another: concentration a chemical that is dissolved: solute

Solid iodide salts react with concentrated sulfuric acid by instantly turning ________________.

dark brown

Ions & Electron Arrangement

dealing with atoms forming ions. (6 of these in practice assignment) - Atoms gain, lose, or share electrons to achieve a noble gas electron arrangement during chemical bonding. K [Ar] 4s1 S [Ne] 3s2 3p4 lose 1e- [Ar] K+ gain 2e- [Ne] 3s23p6 or [Ar] S2- potassium ion sulfide ion

What type of reaction is the following equation? Pb(NO3)2 + 2 NaCl → PbCl2 + 2 NaNO3

double-replacement

Separation of a substance from a mixture by preferentially dissolving in a suitable solvent leaving the insoluble components behind.

extraction

Molar Mass

the mass of one mole of a substance Unit g/mol

Compounds

two or more elements chemically combined at fixed ratio Can be broken into simpler substances by chemical methods only Molecules, groups of atoms bound together, are smallest characteristic particle of most compounds Subscript in molecule formula indicates ratio of each element present - Examples: water H2O magnesium chloride MgCl2

Atmospheric Pressure

measured using a barometer STP: 1 atm at sea level and 273 K (0oC) 1 atm = 760 mmHg = 760 torr 1 atm = 101.3 kPa 1 atm = 14.7 psi

Potassium carbonate contains what % C?

% C = (12.01 g/mol / 138.21 g/mol) x 100 = 8.69% C

Potassium carbonate contains what % K?

% K = total mass K in compound / total mass compound x 100 % K = (78.20 g/mol / 138.21 g/mol) x 100 = 56.58% K

How many moles of H2 can be formed if a 2.25 g sample of Mg reacts with excess HCl?

.093 Mg reacts with HCl to form H2 as shown. Mg+2HCl⟶MgCl2+H2 There is a 1:1 stoichiometric ratio between Mg and H2. Convert the given mass of Mg to moles. This will also give the moles of H2 . 2.25 g Mg × (1 mol Mg / 24.3 g Mg) x (1 mol H2 / 1 mol Mg)

8.0 mL sample of vinegar requires 28.5 mL of a 0.25 M solution of NaOH to reach the endpoint in a titration. What is the molarity of the acetic acid present in the vinegar solution? Express answer to 2 decimal places. Do not enter unit.

.89 .25 M x 0.0285 = 0.007125 mol NaOH0.007125 mol / 0.008 L = 0.890625 aka .89

Perform the calculation, rounding your answer to the proper number of significant figures. 0.32610 ÷ 1.830 =

0.1782 The mathematical operation in the question is division so follow the significant figure rules for multiplication/division, which look at the number of significant figures in each number. The number 1.830 has the fewest significant figures, so the answer can have four significant figures. When performing the calculation, the answer appears as 0.178196172 but you should round it to 0.1782.

A concentrated salt solution has a mass of 5.35 g for a 5.00 mL sample. What is the specific gravity of this solution?

1.07 Specific gravity is equal to the density of the substance divided by the density of water. specific gravity=density of substance / density of water The density of water is known (1.00 g/mL), but the density of the substance must be calculated using the density equation. The density of a substance is equal to mass divided by volume. Density=mass / volume Use the given mass and volume to calculate the density of the salt solution. d=5.35 g / 5.00 mL Divide by 1.00 g/mL to obtain the specific gravity. Note that the units cancel, and the answer is unitless.

A football field is 120 yards by 53.333 yards. What is the area of the football field in acres if 1 acre=43560 ft2? Use correct significant figures when answering this question.

1.3 Note that you should not round your answer to the correct significant figures until the end of the calculation. Start by converting the measured distances from yards to feet by remembering that 1 yard=3 feet. distance in feet=distance in yards×(3 ft / 1 yd) measured side in ft=120 yds×(3 ft / 1 yd)=360 ft other measured side in ft=53.333 yds×(3 ft / 1 yd)=159.9999 ft Then calculate the area of the field in square feet. area in ft2=measured side in ft×other measured side in ft area in ft2=360 ft×159.9999 ft=57596.4 ft2 Finally, convert area in square feet to acres. area in acres=area in ft2×(1 acre / 43560 ft2) area in acres=57596.4 ft2×(1 acre / 43560 ft2) =1.32223 acres=1.3 acres There are only two significant figures in 120 yards so your answer should be reported with two significant figures.

Fluorine-18 is a radioisotope used PET scans. Fluorine-18 has a half-live of 110 minutes. If a sample containing 100 mg of the radioisotope is shipped at 8:00am, how many milligrams of the isotope are still active after 330 minutes?

12.5 mg 330 min / 110 min per half-life = 3 half-lives. 100.0 mg × (1/2) × (1/2) × (1/2) = 12.5 mg

f sublevel can hold a maximum of ? electrons.

14

Calculate the percent by mass of a solution made from 13 g NaCl (the solute) and 64 g water.

17 The definition of percent by mass for a solution is mass of a solution= (mass of solute / mass of solution) ×100 The mass of the solute, NaCl, is given as 13 g. The mass of the solution includes the mass of both the solute and the solvent. mass of solution=mass of solute + mass of solvent = 13 g+64 g Therefore, proper substitution into the defining equation is mass of solution=13 g / (13 g+64 g) ×100

Choose the best graduated cylinder to make each measurement in a single use.

18.5 mL of a NaClNaCl solution - A 25 mL graduated cylinder with markings every 1 mL 36 mL of water - A 50 mL graduated cylinder with markings every 10 mL 5.75 mL of a sucrose solution - A 10 mL graduated cylinder with markings every 0.1 mL

A dialysis unit requires 75,000 mL of distilled water. How many gallons of water are needed? Give the answer to 1 decimal place. Here are available conversion factors: 946 mL = 1 qt 1 gal = 4 qt

19.8 75000 mL / 946 mL = 79.2 qt 79.2 qt / 4 qt = 19.8

Neils Bohr's Explanation

1913, Neils Bohr explained line spectra - Light can have discrete amounts of energy. Energy is quantized. Electrons must have only these quantized energy values illustrated electron energy levels orbiting nucleus modeled after laws of planetary motion. model worked well for hydrogen. received 1922 Nobel Prize in physics

Electron Energy Levels

1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s 4f 5d 6p 7s 5f 6d 7p

Which is the correct electron configuration for zirconium?

1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d2

Stoichiometry Practice

2 Al(OH)3 (s) + 3 H2SO4 (aq) = Al2(SO4)3 (aq) + 6 H2O (l) (Balanced) How many moles of each: 2 mol Al(OH)3: 3 mol H2SO4: 1 mol Al2(SO4)3: 6 mol H2O Example problem: If 3.5 moles of Al(OH)3 completely reacts, how many moles of Al2(SO4)3 are produced? 3.5 mol Al(OH)3 X (1 mol Al2(SO4)3 / 2 mol Al(OH)3) = 1.8 mol Al2(SO4)3

How many grams O2 produced from 3.5 mols KClO3?

2 KClO3 (s) = 2 KCl (s) + 3 O2 (g) How many moles of each: 2 KClO3: 2KCl: 3 O2 3.5 mol KClO3 x ( 3 O2 / 2 KCl) x (32.0 g O2 / 1 mol O2) = 170 g O2

Stoichiometry Practice 2

2 KClO3 (s) = 2 KCl (s) + 3 O2 (g) (Balanced) How many moles of each: 2 mol KClO3: 2 mol KCL: 3 mol O2 Example problem: How many mols KCl from 2.5 mols KClO3? 2.5 mol KClO3 x (2 mol KCl / 2 mol KClO3) = 2.5 mol KCl

Suppose you need to prepare 117.6 mL of a 0.322 M aqueous solution of NaCl. What mass, in grams, of NaCl do you need to use to make the solution?

2.21 The definition of molarity is Molarity=moles of solute / liters of solution Because you know the necessary molarity and volume of solution, you can calculate the moles of NaCl solute. Then, use the molar mass of NaCl to find the required mass. Convert milliliters to liters using the definition of the metric prefix. volume in liters=117.6 mL solution x (1 L /1000 mL) Then, multiply the volume by the molarity to find moles of NaCl. moles of NaCl=117.6 L solution x (0.322 mol NaCl / 1 L of solution) Finally, multiply the moles of NaCl by the molar mass of NaCl to find mass of NaCl. The molar mass of NaCl is 58.435 g/mol. mass of NaCl=moles of NaCl x (58.435 g NaCl / 1 mol NaCl)

Perform the calculation, rounding your answer to the proper number of significant figures. 0.867 + 3.72 + 18.0045 =

22.59 The mathematical operation in the question is addition so follow the significant figure rules for addition/subtraction, which look at the digits past the decimal point. The number 3.72 has the fewest digits past the decimal point, so the answer can have only two digits past the decimal point. When performing the calculation, the answer appears as 22.5915 but you should round it to 22.59.

For each reaction, determine whether it is an example of combustion or not.

2C2H6+7O2⟶4CO2+6H2O2CX2HX6+7OX2⟶4COX2+6HX2O: Combustion C+O2⟶CO2C+OX2⟶COX2: Combustion CO2+4H2⟶CH4+2H2OCOX2+4HX2⟶CHX4+2HX2O: Not combustion 2N2O5⟶4NO2+O22NX2OX5⟶4NOX2+OX2: Not combustion 2NO+O2⟶2NO22NO+OX2⟶2NOX2: Combustion

Calculate the volume, in cubic centimeters, of a box which is 125 cm long, 37 cm wide, and 68 cm high. Report your answer with correct significant figures in cubic centimeters.

310000 To calculate the volume of the box, find the product of the length, the width, and the height of the box. volume of the box=length×width×height volume of the box=125 cm×37 cm×68 cm=310000 cm3 Your answer should be reported with two significant figures because both the width and the height were measured to only two significant figures.

Determine the mass of a sample of aluminum having a volume of 12.1 mL. The density of aluminum is 2.7 g/mL.

32.7 g Density = mass of substance / volume of substance 2.7 g/mL = ? / 12.1 mL 2.7 g/mL x 12.1 mL = 32.7

Which of the following gives the correct numbers of protons, neutrons, and electrons in a neutral atom of this isotope Mo-94?

42 protons, 52 neutrons, 42 electrons

View the photograph below showing a close up view of a green liquid in a graduated cylinder. Which answer is correct based on the devisions on the device. Keep in mind that measurements require estimation so you may not agree "exaclty" on the number for the last digit, but you should agree within a narrow margin of error.

42.3 mL

Determine formula of hydrate of CaSO

5.12 g of hydrate salt (CaSO4 . x H2O) was heated. 4.02 g anhydrous CaSO4 salt remaining after heating. How many moles anhydrous CaSO4 salt remains? 4.02 CaSO4 x (1 mol CaSO4 / 136.15 g/mol) = 0.0295 mol CaSO4 Mass of water driven off? 5.12 - 4.02 = 1.10 g Moles of water were driven off? 1.10 g H2O x (1 mol H2O / 18.02 g H2O) = 0.0610 mol H2O Salt to Water ratio 1:2 0.0610 mol H2O / 0.0295 mol CaSO4 = 2.07 aka 2 Formula for the hydrate: CaSO4 . 2H2O

Identify which balance was used to make each mass reading.

5.43 g: A balance with ±0.01 g tolerance 4.0000 g: A balance with ±0.0001 g tolerance 0.90 g: A balance with ±0.01 g tolerance 6.539 g: A balance with ±0.001 g tolerance 1.230 g: A balance with ±0.001 g tolerance

Rain is labeled as acid rain when the pH is below

5.6

A p sublevel can hold a maximum of ? electrons.

6

Perform the calculation, rounding your answer to the proper number of significant figures. 6.16 - 0.00086 =

6.16 The mathematical operation in the question is subtraction so follow the significant figure rules for addition/subtraction, which look at the digits past the decimal point. The number 6.16 has the fewest digits past the decimal point, so the answer can have only two digits past the decimal point. When performing the calculation, the answer appears as 6.15914 but you should round it to 6.16.

Goldstein's Experiment

Eugen Goldstein, German scientist discovered positively charged particles (1886) Positive particles called Protons

Calculate the percent by mass of Ag in AgNO3 . Express answer to one decimal place without any unit.

63.5 mass of a solution= (mass of solute / mass of solution) ×100107.87 / 169.877 = 0.634 x 100 = 63.5%

The H2 produced in a chemical reaction is collected through water in a eudiometer. If the pressure in the eudiometer is 760.0 torr and the vapor pressure of water under the experimental conditions is 23.1 torr, what is the pressure (torr) of the H2 gas?

736.9 The total pressure is equal to the pressure of the water vapor plus the pressure of the hydrogen gas. Ptotal=PH2O+PH2 Subtract the pressure of the water vapor from the total pressure to find the pressure from the H2 Ptotal−PH2O=PH2 760.0 torr−23.1 torr

An inhalation anesthetic is mixed with oxygen. The partial pressure of oxygen is 520 mmHg and the anesthetic is 240 mmHg. What is the total pressure of the mixture?

760 mmHg

Determine the Molecular Formula 92.20 g C & 7.76 g H

92.2 g C x (1 mol / 12.01 g/mol) = 7.68 mol C 7.76 g H x (1 mol / 1.01 g/mol) = 7.68 mol H (Divide by the smallest) 7.68 mol C / 7.68 mol H = 1 7.68 mol H / 7.68 mol H = 1 Empirical Formula: CH Molar mass: 12.01 g C + 1.01 g H= 13.02 g/mol To get Molecular divide the given mass from the empirical mass. 78.12 g/mol / 13.02 g/mol = 6 Molecular Formula: C6H6

How many electrons does an atom of plutonium contain?

94

Symbols for Isotopes

A = mass number Z = atomic number X = symbol of element

A mile is defined as 5280 feet. This number ? which means that it has ? significant figures.

A mile is defined as 5280 feet. This number is an exact number which means that it has infinite significant figures.

Energy

Ability to do work, change matter, or transfer heat Classifications - Kinetic: energy of motion - Potential: stored energy or energy at rest accompanies physical or chemical changes Absorbed/Released during chemical reactions SI unit joule (J) common unit calorie (cal)

According to Le Châtelier's Principle, heat applied to an exothermic reaction will shift the reaction towards ?. Heat applied to an endothermic reaction will shift the reaction towards ?.

According to Le Châtelier's Principle, heat applied to an exothermic reaction will shift the reaction towards the reactants. Heat applied to an endothermic reaction will shift the reaction towards the products.

Titration- volumetric analysis

Acid-Base titration using phenolphthalein as indicator HC2H3O2 (aq) (Acid) + NaOH (aq) (Base) = NaC2H3O2 (aq) + H2O (l) (Water)

Neutralization

Acids and bases neutralize one another Example: NaOH (aq) (Base) + HCl (aq) (Acid) = NaCl (aq) (Salt) + H2O (Water)

Formulas of Acids & Bases

Acids: cation (H+, hydrogen ion) goes first anion goes last. Ionizable Acids: H2SO4, HNO3, HC2 Nonionizable Acids: H3O2, NH3, CH4 Bases: same rules as ionic or covalent compounds In organic chemistry it could be written as CH3O2 or CH3OOH. This shows that are an acidic acid.

Acid & Base Properties

Acids: turns litmus red, taste sour, neutralize bases, electrolytes, corrosive Bases: turns litmus blue, taste bitter, neutralize acids, electrolytes, corrosive

Significant Figures in Calculations 2

Addition and Subtraction with decimal place Answer should have same number decimal places as measured number with fewest number decimal places. 250 cm + 7.6 cm 257.6 cm = no decimal place Answer should have same number trailing zeros as measured number with largest number trailing zeros.

Hydrogen Bonds

Additional polar attraction When H atom covalently bonded to N, O, or F

Law of Multiple Proportions

Elements may combine in more than one set of definite proportion Example: Nitrous Oxide, Nitric Oxide, Nitrogen Dioxide. All have oxygen and nitrogen in them.

Distance Radiation Travels

Alpha radiation least penetrating can penetrate the outer layer of skin. stopped by a sheet of paper. Beta radiation can penetrate through several cm of skin & tissue. stopped by a sheet of aluminum foil. Gamma radiation will pass right through a body. requires several cm of Pb to stop.

Avogadro's Law

Amedeo Avogadro explained the law of combining volumes in 1811 with his hypothesis relating amount of gas & volume when temperature and pressure constant volume directly proportional to amount (n) in number of moles V/n = constant V1 / n1 = V2 / n2

Discovery of Radioactivity

Antoine Henri Becquerel (1852-1908), French physicist, - found uranium ores fog photographic plates in dark Radioactivity - spontaneous emission of radiation from certain unstable elements Marie Curie, Polish, & husband Pierre Curie, French - discovered other radioactive elements Becquerel & both Curies shared 1903 physics Nobel prize Marie Curie awarded second Nobel prize for chemistry in 1911.

Mendeleev's Periodic Table

Arranged in order of increasing mass and by chemical property

Atoms & Molecules

Atoms - Symbol Pt represents a platinum atom - Symbol H represents a hydrogen atom Molecules: Group of atoms bonded together - Represented by chemical formulas Formula H2 represents a hydrogen molecule In hydrogen peroxide, H2O2 - there are 2 atoms of O and 2 atoms of H

Octet Rule

Atoms gain, lose, or share electrons to achieve a noble gas electron arrangement during chemical bonding. 5 Atoms with similar (high) electronegativities share electrons to form covalent bonds. Nonmetal + Nonmetal Covalent compounds also called molecular compounds

Electronegativities & Bond Types

Atoms with very different electronegativities exchange electrons to form ionic bonds. Atoms with similar (high) electronegativities share electrons to form covalent bonds. Metal + Nonmetal(s) Nonmetal + Nonmetal Covalent bonds & compounds Ionic bonds & compounds

A substances that gives hydroxide ions in aqueous solutions is a(n)

Base

What is the name of the compound with the formula of BF3?

Boron trifluoride

Hyperbaric Chambers

Boyle's Law, Henry's Law, and Dalton's Law are all related to these chambers. Decompression: reduction of pressure, Reduces amount gas dissolved in blood, Must be done slowly Greater oxygen pressures: Increases amount oxygen dissolved

A gas at 500.0 mL and 3.0 atm is compressed to 295.0 mL. What is new pressure if amount & temp. constant?

Boyle's Law. P1V1 = P2V2 3.0 atm x (500.0 mL / 295.0 mL) = 5.1 atm

Energy in Chemical Reactions

Breaking and forming bonds during reactions involves energy changes heat of reaction activation energy: - energy needed to initiate reaction or break bonds of reactants. heat of reaction: - difference in energy between reactants and products. (Overall energy change)

Buffers

Buffers resist change in pH A buffer system consists of a conjugate acid-base pair. a weak acid + salt providing common ion or a weak base + salt providing common ion

Which compounds could be represented by the empirical formula CH2?

C3H6 C2H4 C8H16 An empirical formula is the most reduced ratio of the elements in a compound. Any molecular formula that can be reduced by a common factor to CH2 has that empirical formula. Therefore, C3H6, C2H4, and C8H16 all have the same empirical formula given in the question. The empirical formula for C2H6 is CH3, the empirical formula forC8H18 is C4H9, and the empirical formula for C2H2 is CH.

What is the empirical formula for hexane which has a true molecular formula of C6H14 ?

C3H7

Determine each type of reaction.

CaCl2(aq)+Na2CO3(aq)⟶2NaCl(aq)+CaCO3(s)CaClX2(aq)+NaX2COX3(aq)⟶2NaCl(aq)+CaCOX3(s): Double replacement 2C2H2(g)+5O2(g)⟶4CO2(g)+2H2O(l)2CX2HX2(g)+5OX2(g)⟶4COX2(g)+2HX2O(l): Combustion 2Fe(s)+6HCl(aq)⟶2FeCl3(aq)+3H2(g)2Fe(s)+6HCl(aq)⟶2FeClX3(aq)+3HX2(g): Single replacement CO(g)+2H2(g)⟶CH3OH(l)CO(g)+2HX2(g)⟶CHX3OH(l):Combination NH4NO3(s)⟶N2O(g)+2H2O(l)NHX4NOX3(s)⟶NX2O(g)+2HX2O(l): Decomposition

Determine whether the given compound name or formula contains a polyatomic ion.

Calcium hydroxide: Contains a polyatomic ion Sodium phosphide: Does not contain a polyatomic ion NH4Cl: Contains a polyatomic ion SO3: Does not contain a polyatomic ion KCN: Contains a polyatomic ion Magnesium sulfate: Contains a polyatomic ion

Naming Practice: Ionic Compounds 2

Can you name these 5 ionic compounds? Ag2Se - Silver Selenide CuO -Copper(II) oxide Cu2O - Copper(I) oxide NH4Cl - Ammonium chloride Ba3(PO4)2 - Barium phosphate

Formula Practice

Can you write formulas for these 5 ionic compounds? zinc oxide - Zn2+ O2- ZnO manganese(IV) telluride - Mn4+ Te2- MnTe2 lithium phosphide - Li+ P3- Li3P

Physical Change

Change in physical property without change in composition Same substance present Examples - Ice melts - Sugar dissolves in water

Which gas law describes the direct relationship between changes in volume and absolute temperature of a gaseous substance when pressure and amount remain constant?

Charles' Law

Chemical Properties

Chemical behavior: how substance reacts with other types of matter, ability to form new substance Iron - rusts (combines with oxygen to form iron oxide) Carbon - burns (combines with oxygen to form carbon dixoide) Silver - tarnishes (combines with sulfer to form silver sulfide) Nitroglycerin - explodes (decomposes to produce a mixture of gases) Carbon Monoxide - is toxic (combines with hemoglobin, causing anoxia) Neon - is inert (does not react with anything)

Scientific Method

Chemistry is just one science that uses the scientific method. Critical thinking process - looking for an explanation for observation - problem solving - designing new product Evidence - Based Approach

Chemistry

Chemistry is the study of the composition, structure, properties and reactions of matter. Study of matter - Physical Properties - Chemical Properties • Changes of matter - Physical Changes - Chemical Changes Energy associated with changes

Examples of Other Important Metals/Ores

Chromium - Cr - FeCr2O4 - Shiny, resists corrosion, Typical Uses Chrome plating, stainless steel Gold - Au - Au - Yellow metal, soft, dense - Typical Uses Coinage, jewelry, dentistry Lead - Pb - PbS - Low-Melting, dense, soft - Typical Uses Plumbing, batteries Magnesium - Mg - MgCl2 - Light, Strong - Typical Uses Auto wheels, luggage Mercury - Hg - HgS - Dense Liquid - Typical Uses Thermometers, barometers Nickle - Ni - NiS - Resists corrosion - Typical Uses Coinage, alloy for stainless steel Platinum - Pt - Pt - Inert, high-melting - Typical Uses Catalyst, instruments Silver - Ag - AgS - Excellent Electric Conductor - Typical Uses Electric contacts, mirrors, jewelry, coins Sodium - Na - NaCl - Reactive, soft - Typical Uses Heat-transfer medium, reducing agent Tin - Sn - SnO2 - Resists corrosions - Typical Uses Coating for steel cans Tungsten - W - CaWO4 - Very high-melting - Typical Uses Light-bulb filaments Uranium - U - U3O8 - Fissionable - Typical Uses Energy Source Zinc - Zn - ZnS - Forms protective coating - Typical Uses Galvanizing coating

When using a properly stabilized balance, how should you ensure that you get the most accurate mass reading possible?

Close the side shields on the balance during reading. Measure the mass of the sample at room temperature. To get the most accurate readings, you should diminish any unusual environmental factors, such as abnormal temperatures or air currents. Measure samples at room temperature to avoid convection currents from a heated sample affecting the reading. Close the side shields on any balance that has them while making a measurement to decrease impact from any air flow. Your sample should be placed in the middle of the balance pan. A properly stabilized balance will be balanced with this ideal placement. The balance should also be stabilized on the table without you leaning on it. Leaning on the table might actually destabilize the balance.

Shells (Energy Levels)

Elements that have more than one electron • Placed into shells - Shells numbered 1, 2, 3, ... - Have 2n2 electrons/shell How many electrons can third shell hold? 2n^2 = 2 (3x3) = 18 Add electrons to the lowest shell until filled, then go to the next shell

Water layer vs. Gaseous Layer!

Compare Pressures of Gases above liquid on each side Buret open to atmosphere Eudiometer closed to atmosphere Compare Pressures of Gases above liquid on each side. "Think altitude/elevation changes" Higher altitude Up the mountain Lower P Lower altitude Down in valley Higher P

Container & Pressure of Gas

Container Open to Atmosphere Internal Pressure = atmospheric pressure Sealed not under pressure (volume can change) Internal pressure = atmospheric pressure Sealed under pressure (no volume change) Need pressure gauge

Determine whether each statement describes a solution of a strong electrolyte, weak electrolyte, or non-electrolyte.

Contains a complete solute: Nonelectrolyte solution Contains a partially dissociated solute: Weak electrolyte solution Has little or no conductivity: Nonelectrolyte solution Contains a completely dissociated solute: Strong electrolyte solution Has a medium level of conductivity: Weak electrolyte solution Has the highest conductivity: Strong electrolyte solution

Nonpolar vs. Polar

Covalent Bonds - Nonpolar (no dipole) equal sharing between atoms of same electronegativity - Polar (has dipole) unequal sharing between atoms of different electronegativity Compound/Molecules (depends on bond type and shape) - Nonpolar: electrically symmetric Polar: electrically asymmetric (unequal)

A 7.298 g sample of copper reacts with oxygen, forming a copper oxide. The final mass of the copper oxide is 8.217 g. What is the formula of the copper oxide?

Cu2O Divide the mass of the copper sample by the atomic mass of copper (63.546 g/mol) to find the number of moles. 7.298 g× (1 mol / 63.546 g) =0.1148 mol Cu Subtract the mass of the copper from the mass of the copper oxide to find the mass of oxygen. Divide this mass by the atomic mass of oxygen (15.999 g/mol) to find the number of moles of oxygen. 8.217 g−7.298 g=0.919 g O 0.919 g× (1 mol / 15.999 g) =0.0574 mol O Find the mole ratio of Cu to O. 0.1148 mol Cu / 0.0574 mol O=2 An empirical formula gives the smallest whole-number ratio. The formula that is consistent with a Cu:O ratio of 2:1 is: Cu2O

Applications

Dating - calculating age Medical Energy Irradiated Foods

This is the process of separating a liquid from a solid (sediment) by gently pouring the liquid from the solid so as not to disturb the solid.

Decantation

Student of Leucippus, a Greek philosopher around 450 B.C.E., referred to indivisible particles of matter as atomos.

Democritus

Consider the trendline on a graph of Mass vs. Volume of a solid or a liquid. What information can be obtained about the substance from the slope of this line?

Density Recall that the formula for a trendline is y=mx+b, where y represents the value on the y-axis, x is the value on the x-axis, m is the slope, and b is the intercept, which should be 0 on a Mass vs. Volume graph. The slope is therefore equal to y divided by x, or mass divided by volume. This value is equal to the density of a substance.

Molar Mass Determination

Determine by adding periodic table mass for each atom in formula

What is the correct reading of the volume in the pictured buret?

Determine the volume in the buret based on the bottom of the meniscus. Note that volume markings increase going down the buret. Therefore, with the meniscus above the 26 mL line, the correct volume is less than 26 mL. The bottom of the meniscus falls right at the sixth tick mark below 25 mL, which corresponds to 25.6 mL. Therefore, a good estimate of the volume is 25.60 mL. You should always report the reading with one estimated digit past the smallest marking by noticing where the bottom of the meniscus falls between the tick marks.

Determine whether each of the given characteristics refers to electrolytes or non-electrolytes.

Dissociate in solution: Electrolytes Do not dissociate in solution: Non-electrolytes Conduct electricity in solution: Electrolytes Do not conduct electricity in solution: Non-electrolytes Examples include: C6H12O6 and CCl4: Non-electrolytes Examples include: NaOH and KBr: Electrolytes

Length

Distance - length, width, height, diameter, circumference - Base SI & metric unit is meter (m) - Commonly used prefixes • kilometer 1000 m = 1 km • centimeter 0.01 m = 1 cm or 100 cm = 1 m - Not commonly used in chemistry laboratory - Ruler or meterstick is used to measure

Determine Polarity?

Does I2 have a polar or nonpolar bond? Is I2 polar or nonpolar? 1 non-polar bond: Non-polar molecule Does PBr3 have polar or nonpolar bonds? Is PBr3 polar? Pyramidal with 3 polar bonds: Polar molecule. Does CF4 have a polar or nonpolar bonds? Is CF4 polar? Tetrahedral 4 polar bonds: Non-polar molecule

Element Families & The Periodic Table

Each column is a group or family: Elements in each group have similar properties Common groups: alkali metals, alkaline earth metals, halogens, and noble gases Each row is a period: Properties vary across period

Subshells

Each orbital (subshell) can contain two e- Orbital shape determines subshell type - Can have s, p, d, f, g, ... sublevels Add electrons to the lowest subshell until filled, then go to the next subshell s holds 2 e-: 1s = 2e- p set of three, can hold 6 e-: 2s+2p = 8e- d set of five, can hold 10 e-: 3s+3p+3d = 18e- f set of seven, can hold 14e-: 4s+4p+4d+4f = 32e-

Spaceship Earth

Earth is divided into three main regions: 1. The crust is the outer shell, atmosphere the air surrounding Earth, hydrosphere makes up the water, lithosphere is the land masses 2. The mantle consists mainly of iron and magnesium silicates 3. The core is largely iron and nickel and is not accessible.

Electricity and the Atom

Electricity not used in laboratories until 19th century - Not common in households until 1930's Volta invented an electrochemical cell in 1800 - Similar to a battery - In a battery Electric current supplied by chemical reactions

Electrolyte vs. Nonelectrolyte

Electrolyte - ions present Nonelectrolyte - no ions present

Ground and Excited States

Electrons "prefer" lowest energy level - Ground state - levels closest to nucleus Excited state - electron goes from lowest energy level to a higher energy level (excited state) - Shifts back to lower energy levels from excited state generates light

Elements and Symbols

Element - Simplest pure substance Chemical symbol - one or two letter abbreviations for an element. - first letter always capitalized - second letter always lower case, if it has one Co element cobalt - CO compound carbon monoxide -

Exact Numbers and Measured Numbers

Exact numbers - obtained by counting or from a definition comparing two units in the same measuring system. No uncertainty in an exact number. Measured numbers - obtained using measuring device/tool. Always uncertainty in a measured number. Final digit recorded in measured number is estimated value.

A mixture of two or more elements, at least one of which is a metal, is called a(n) ________ .

Examples: Fe + C → Steel Cu + Sn → Bronze Cu + Zn → Brass Pb + Sn → Pewter, solder Au + Ag → White gold a. Allotrope b. Alloy c. Homogenate d. Emulsion e. Composite Correct: b. Alloy

Chemical equilibrium occurs when the forward rate is equal to the reverse rate in a reversible reaction. True or false, the amount of reactants and products are always equal at equilibrium?

False

The predominant rocks and minerals in the earth's crust are silicates, carbonates, oxides and sulfides. Classify the following minerals by matching them to the correct type of mineral based on their element composition. Some choices will be used more than once.

Fe2O3 - oxide Cu2S - sulfide ZrSiO4 - silicate CaCO3 - carbonate MnCO3 - carbonate U3O8 - oxide

This is the process of separating a solid from a liquid by means of a porous material.

Filtration

The label and SDS for the chemical amyl acetate contain the signal word "WARNING" and this pictogram. What type of warning hazard is meant by this pictogram? (picture of a flame over a rectangle)

Flammable

Ionic Compounds with Polyatomic ions

Follow rules for writing names and formulas for ionic compounds. Name these compounds Write formulas NiSO4 - Nickle (II) Sulfate Na2CO3 - Sodium Carbonate chromium(III) hydroxide - Cr(OH)3 molybdenum(II) nitrite - Mo(NO2)2

Learning Check

For each of the following, indicate whether the unit describes length, mass, temperature or volume. V 1. A bottle contains 1.5 L of water. M 2. A medication contains 0.50 g aspirin. L 3. A person is 2.0 m tall. T4. The liquid boiled at 351 K

State of matter which does not have definite shape nor definite volume.

Gas

Which gas law describes the direct relationship between changes in pressure and absolute temperature of a gaseous substance when volume and amount remain constant?

Gay-Lussac's Law

Polyatomic Ions

Group of atoms with ionic charge

At constant temperature and pressure, the volumes of gaseous reactants and products are in small whole-number ratios according to

Guy Lussac's law of combining volumes

Effects of Changes in Equilibrium

H2 + Cl2 -> 2 HCl + 44 kcal - exothermic What is effect on equilibrium if: HCl added <- Cl2 removed <- Lower temperature ->

Which of the following substances is an acid?

H2SO4

Examples

HCl - Hydrochloric Acid HClO3 - Chloric Acid HClO2 - Chlorous Acid

Which is the correct formula for chlorous acid?

HClO2

Brønsted-Lowry Acids & Bases

HF (g) (Donates the H+: Acid) + H2O (l) = H3O+ (aq) + F- (aq) (Conjugate: Base) NH3 (g) (Accepts the H+: Base) + H2O (l) = NH4+ (aq) (Conjugate: Acid) + OH- (aq) NH3 (g) (Accepts H+: Base) + HF (aq) (Donates H+: Acid) = NH4+ (aq) + F- (aq)

Identify whether each substance is an acid or base.

HNO2: acid HClO4: acid KOH: base Ba(OH)2: base RbOH: base

Endothermic Reactions

Heat absorbed from surroundings. Reactants + Heat -> Products

The amount of a gas dissolved in a liquid will decrease as the vapor pressure decreases according to

Henry's Law

Draw the Lewis electron dot structure for SCl2 on scratch paper with S in the center. Answer the following questions about the SCl2 Lewis structure by entering the number for the answer in the box after the question. (A) How many total valence electrons are available for the Lewis structure? [A] (B) How many lone pairs of electrons are on the S atom in the SCl2 Lewis structure? [B] (C) How many lone pairs of electrons are on each Cl atom in the SCl2 Lewis structure? [C](Not the total for both Cl combined.)

How many total valence electrons are available for the Lewis structure? [A] -20 How many lone pairs of electrons are on the S atom in the SCl2 Lewis structure? [B] - 2 How many lone pairs of electrons are on each Cl atom in the SCl2 Lewis structure? [C](Not the total for both Cl combined.) - 3

Balancing Chemical Equations

Hydrogen reacts with oxygen to produce water Must have same number atoms of each element on both sides of equation

Diatomic Elements

Hydrogen, nitrogen, oxygen, and halogens exist in nature as diatomic molecules, two atom molecules. nonmetal atoms of the same element held together by sharing electrons H2 , N2 , O2 , F2 , Cl2 , Br2 , I2

Match the correct name with the correct formula.

I- Iodide Cl¯ Chloride SO42¯ Sulfate CO32¯ Carbonate

Which of the following substances would be more soluble in a nonpolar solvent?

I2

LabFlow Lab 8 report does ask a question about equilibrium.

If LeChatlier's principle indicates the reaction is shifting forward the K must be increasing. K increases when the forward reaction is favored and more products form. If LeChatlier's principle indicates the reaction is shifting in reverse the K must be decreasing. K decreases when the reverse reaction is favored and more reactants form.

Some Other Gas Laws: Combined

If only the amount of gas remains constant, pressure, volume, and temperature of gas can be combined into one relationship called the combined gas law. P1V1 / T1 = P2V2 / T2

Consider the two reactions of iron ions, one with thiocyanate (SCN−) ions and one with chloride (Cl−) ions. Fe3+ +SCN−−⇀↽−FeSCN2+ Fe3++4Cl−−⇀↽−FeCl4− If you create an equilibrium mixture from Fe3+ and SCN ions, adding Cl− ions will

If you create an equilibrium mixture from Fe3+ and SCN− ions, adding Cl− ions will shift the iron-thiocyanate equilibrium to the reactant side because it removes iron from the iron-thiocyanate equilibrium mixture.

What are minor components in a mixture called?

Impurities

Determine the number of significant figures in each measurement. Then, choose the representation of the number where x is in place of the estimated digit from the measurement.

In 14.8 m, there are 3 significant figures. All the digits are non-zeros and are significant. In $10.25, there are 4 significant figures. The only zero in the measurement is between two non-zero digits and is, therefore, significant. In 0.05 L, there is only 1 significant figure. Neither zero is significant because they both appear to the left of all the non-zero digits. In 1.000 g/mL, there are 4 significant figures. All the zeros are significant because they appear to the right of the non-zero digit and there is a decimal point present. In 6200 cm, there are 2 significant figures. The zeros are not significant because they appear to the right of non-zero digits but there is no decimal point present. In 403 kg, there are 3 significant figures. The zero is significant because it appears between two non-zero digits. In all the measurements, the last significant digit, whether a zero or not, is the estimated digit.

For each described liquid, determine the behavior of a hydrometer calibrated around the density of pure water.

In a liquid that is less dense than water: Float lower than position in pure water In a liquid with the same density as water: Float in the same position as pure water In a liquid that is more dense than water: Float higher than position in pure water

Experimental Determination of Concentration

In a neutral solution [H3O+ ] = [OH- ] moles (acid) = moles (base) Equivalents (acid) = Equivalents (base) MaVa= MbVb Equivalents = moles electrical charge

In the context of a balanced chemical equation, a ? is a number to the lower right of an element or ion within formula and it applies to ? A ? is a number to the left of a formula and it applies to ? Only ? should be added or changed when balancing chemical equations.

In the context of a balanced chemical equation, a subscript is a number to the lower right of an element or ion within formula and it applies to only the part of the formula it follows. A coefficient is a number to the left of a formula and it applies to the entire formula it precedes. Only coefficients should be added or changed when balancing chemical equations.

Glass

Inorganic materials melted together, then cooled to hard transparent solid. "Super-cooled liquid"!

Intermolecular Forces

Intermolecular forces: attractive forces holding hold molecules together strength determines state of matter affect energy requirements for change in state melting points boiling points

Solving Stoichiometry Problems

Involve these steps: 1) Always use a Balanced Equation 2) Convert given quantity to moles 3) Convert moles given substance to moles desired substance 4) Convert moles of desired substance to grams 2A + B = A2B First Mass of A in grams then use molar mass as a conversion factor (mol A / g A) Second Amount of A in moles Third 1 mol of B is equal to 2 mol of A. These are the coefficients from the balanced equation. Amount of B in moles. Fourth Mass of B in grams using molar mass as the conversion factor. (g B / mol B). This gets mass of B in grams.

Attractive Forces: Ionic vs. Molecular

Ionic Compounds - Ionic bonds Very strong attractions between positive and negative ions - Solids at room temperature Crystalline, hard and brittle High melting points - NaCl melting point 801 o C Molecular Compounds (Covalent Compounds) - Covalent Bond holds atoms together in molecules - Weaker intermolecular attractions between molecules - Some are liquids or gases at room temperature Lower melting and boiling points Solids are usually softer than ionic compounds

Illustration

J. J. Berzelius (1779-1848), Swedish chemist Heated a quantity of lead with sulfur

Bronsted-Lowry Theory in 1923

J.N. Bronsted - Denmark T.M. Lowry - Great Britain Acids - donate protons (hydrogen ions, H+). Bases - accept protons (hydrogen ions, H+). In water, protons (H+) form H3O+, hydronium ions.

Charles' Law

Jacques Charles, French physicist, studied temperature & volume of gas when pressure and amount constant volume directly proportional to absolute T V/T = constant V1 / V2 = T1 / T2

Law of Combining Volumes

Joseph Louis Gay-Lussac (1778-1850), French, Carried out chemical reactions with gases. He summarized his findings in 1809. law of combining volumes: At same temperature & pressure, volumes of gaseous reactants & products are in small whole-number ratios.

J. J. Thomson's Experiment

Joseph Thomson (1856-1940) English physicist discovered negatively charged particles - Electrons calculated mass-to-charge ratio of electrons received 1906 physics Nobel prize

Calculate molar mass of potassium carbonate?

K2CO3 (Potassium Carbonate) 2 Potassium= 78.20 g/mol 1 Carbon= 12.01 g/mol 3 Oxygen= 48 g/mol Total: 138.21 g/mol

Kinetic Molecular Theory

KMT 1. particles of gas are in rapid constant motion. 2. particles of gas are tiny compared to distance between them. 3. little attraction between particles of gas. 4. Collisions between gas molecules are perfectly elastic. 5. Temperature is measure of the average kinetic energy of gas molecules.

Identify the correct equation for the equilibrium constant Kc for the reaction given. Cu(s)+2AgNO3(aq)−⇀↽−Cu(NO3)2(aq)+2Ag(s)

Kc=[Cu(NO3)2] / [AgNO3]2

Law of Conservation of Mass

Lavoisier summarized quantitative findings -Law of Conservation of Mass (Matter) Matter not created nor destroyed during chemical change Basis for many chemical calculations and balancing chemical equations Make new materials by rearranging atoms not creating atoms

The fact that 4 g of hydrogen (H2) reacts with 32 g of oxygen (O2) to give 36 g of water is an illustration of what law?

Law of conservation of mass Law of definite proportions Law of multiple proportions Law of combining elements The periodic law Correct: Law of conservation of mass

The tarnish on silverware is primarily silver sulfide, which always forms with a 2:1 ratio of Ag to S. This is an example of what principle?

Law of conservation of mass Law of definite proportions Law of multiple proportions Law of combining elements The periodic law Correct: Law of definite proportions

Missing Elements

Left gaps in order to place elements with similar properties in correct locations in the table Predicted properties of missing elements - for example, germanium: Atomic mass - 72 (Predicted) - 72.6 (Observed) Density (g/cm3) - 5.5 (Predicted) - 5.47 (Observed) Color - Dirty gray (Predicted) - Grayish white (Observed)

Limitations, Risks, & Benefits of Science

Limitations - variables change over course of experiment Benefits - promote well-being or have positive effect Risks - hazards that lead to loss or injury

Writing Keq Expressions

Look at this silver chloride reaction with ammonia. AgCl (s) + 2 NH3 (aq) = Ag(NH3)2 +1 (aq) + Cl -1 (aq) The equilibrium constant expression: K eq = [Ag(NH3)2 +1] [Cl -1] / [NH3 ] 2 If K is greater than 1, the forward reaction is favored. If K is smaller than 1, the reverse reaction is favored.

Density (continued)

Lower density objects float on higher density subtances - Objects less dense than water float • Ice, wood - Objects more dense than water sink • Copper, gold, lead

Mass is conserved in an experiment if the ? of the individual component masses equals the mass of the ?.

Mass is conserved in an experiment if the sum of the individual component masses equals the mass of the mixture of the components.

Law of Conservation of Mass/Matter

Matter is not created nor destroyed during chemical change atoms rearrange Equations must be balanced!

Lab Titration Determination % acid in Vinegar

MbVb= molesb b = Base (Moles x L) / L = Moles moles (base) = moles (acid) moles (acid) x molar mass (acid) = grams (acid) %= (mass acid x 100) / mL acid

Periodic Table by Metallic Properties

Metals - Characteristic luster - Good conductors of heat and electricity - Solid at room temperature, except mercury Nonmetals - Dull in appearance - Poor conductors of heat and electricity Metalloids (semi-metals) - Properties between the other classes

Predict the products of hydrobromic acid, HBr, reacting with magnesium hydroxide, Mg(OH)2.

MgBr2 and H2O Magnesium hydroxide is Mg(OH)2 and hydrobromic acid is HBr. Neutralization reactions are a type of double replacement reaction, where the ions switch partners. One product is the combination of a hydrogen cation and the hydroxide anion, which is water, H2O. The other product is the combination of magnesium ions and bromide ions. Magnesium ions have a +2 charge and bromide ions have a -1 charge, so the correct formula is MgBr2. The overall balanced equation is 2HBr+Mg(OH)2⟶MgBr2+2H2O

How many grams of AgNO3 need for 27.3 g MgCl2?

MgCl2 (aq) + 2 AgNO3 (aq) = Mg(NO3)2 (aq) + 2 AgCl (s) How many moles of each: 1 MgCl2: 2 AgNO3: 1 Mg(NO3)2+ 2AgCl 27.3 g x (1 mol MgCl2 / 95.21 g MgCl2) x (2 mol AgNO3 / 1 mol MgCl2) x (169.88 g AgNO3 / 1 mol AgNO3)= 97.42 g AgNO3

How many grams of AgCl from 27.3 g MgCl2?

MgCl2 (aq) + 2 AgNO3 (aq) = Mg(NO3)2 (aq) + 2 AgCl (s) How many moles of each: 1 MgCl2: 2 AgNO3: 1 Mg(NO3)2: 2 AgCl 27.3 g MgCl2 x (1 mol MgCl2 / 95.21 g MgCl2) x ( 2 mol AgCl / 1 mol MgCl2) x (143.4 g AgCl / 1 mol AgCl) = 82.2 g AgCl

Mass of Electron

Millikan was able to determine mass of electron using Thomson's mass to charge ratio Mass of electron calculated to be 9.1 x 10-28 g 1837 times smaller than a proton 0.0005 amu (0 amu) Mass of proton 1.7 x 10 -24 g 1 amu

Dalton's Law

Mixture of gases, total pressure equals sum of partial pressures. PT = P1 + P2 + P3 + P4+ etc. Example: Helium and Argon in one tank. P(He) = 2 atm P(Ar) = 4 atm P(Total) = 2 atm +4 atm = 6 atm

Which of the following compounds requires a Roman numeral in its name?

MnO2 The Roman numeral in the name of the compound indicates the charge of a cation. It is only necessary if the metal element can form cations with multiple different charges. In general, you are looking for a transition metal cation in the compound as most of the transition metals can have many different oxidation states or charges. Therefore, MnO2 is the compound that needs a Roman numeral in its name. The cation comes from manganese, which can have multiple different oxidation states. The name of MnO2 is manganese(IV) oxide, where the Roman numeral "IV" indicates that the cation present is Mn4+. The charge of the cation can be determined by knowing the -2 charge of the oxygen ion and knowing the formula, which contains the ions in the ratio necessary for a neutral unit. The other compounds are all examples of other ionic compounds, as demonstrated by the presence of metal elements combined with a non-metal element or an anionic polyatomic ion. The cation in each of these compounds comes from an element that only has one stable ionic charge, so the charge does not need to be indicated in the name. The correct name of MgCl2 is magnesium chloride, the correct name of Al(NO3)3 is aluminum nitrate, and the correct name of Na2O is sodium oxide.

Most of the ? people encounter in everyday life consists of ? of different substances.

Most of the matter people encounter in everyday life consists of mixtures of different substances.

Mole Relationships in Reactions

NH3 + O2 = HNO3 + H2O (Not Balanced) NH3 + 2O2 = HNO3 + H2O (Balanced) 1 mol NH3: 2 mol O2: 1 mol HNO3: 1 mol H2O Compare Quantities 1 mol NH3 / 2 mol O2 or 2 mol O2 / 1 mol NH3 (Whatever you are solving for you want it in the numerator) Ratio: 1:2:1:1

Which of these are acid? Which are bases?

Na2SO4 - Salt KOH - Base H3PO4 - Acid LiNO3 - Salt NH3 - Base HBr - Acid

Determine what type of reaction each unbalanced chemical equation represents.

NaHCO3⟶CO2+NaOHNaHCOX3⟶COX2+NaOH: Decomposition Mg+H2SO4⟶MgSO4+H2Mg+HX2SOX4⟶MgSOX4+HX2: Single replacement CaCl2+Na3PO4⟶Ca3(PO4)2+NaClCaClX2+NaX3POX4⟶CaX3(POX4)X2+NaCl: Double replacement AgNO3+NaCl⟶NaNO3+AgClAgNOX3+NaCl⟶NaNOX3+AgCl: Double replacement

Determine whether or not each chemical formula is an empirical formula.

NaMnO4: Empirical formula Ba3(PO4)2: Empirical formula C6H12O6: Not an empirical formula CaCO3: Empirical formula K2C2O4: Not an empirical formula

Chemical Reactions Involve Chemical Changes

New substance has different physical and chemical properties than original substance(s). Changes may involve: Color changes Bubbles as gas evolves Formation of a solid Temperature changes

Stable Electron Configurations

Noble gases: stable elements, do not form compounds # valence electrons: He 2 Ne 8 Ar 8 Kr 8 Xe 8 Rn 8

Anhydrides: without water

Nonmetal Oxides: - React with water to form acids CO2 (Acidic Anhydride) + H2O = H2CO3 (Forms an acid) Metal Oxides: - React with water to form bases MgO (Basic Anhydride) + H2O = Mg(OH)2 (Forms a Base)

Covalent Compound Bonding Electron Dot Structures

Nonmetal lower in electronegativity or element needing more electrons is usually in center. Hydrogen should never be in center of structure. Try to draw ammonia and carbon monoxide Lewis Dot (electron dot) structures

Atomic Number

Number protons in atom = atomic number whole number on periodic table atoms of same element have same atomic # Neutral atom #protons = #electrons

Ionic Compound Name

Only indicates which ions present Naming Rules: Name cation first followed by anion (two words). Omit word "ion" in compound name. Ionic Compound Example: calcium phosphate Name does NOT indicate how many of each ion

Table 12.2

Oxide: Hematite - Fe2O3 - Ore of iron, pigment Magnetite - Fe3O4 - Ore of iron Corundum - Al2O3 - Gemstone; Abrasive Sulfide: Galena - PbS - Ore of Lead Chalcopyrite - CuFeS2 - Ore of Lead, Ore of Copper Carbonate: Calcite - CaCO3 - Cement; Lime

pH Scale

P. L. Sorensen, a Danish biochemist, described acidity and basicity using pH scale in 1909. pH = - log [H3O+ ]

What is the pressure of 0.50 g CO2 if 250.0 mL is at 298 K?

PV= nRT First: Molar mass for CO2: Mass given / Molar mass. .50 g / 44.01 g = 0.01136 mol Second: Convert mL to L. Divide mL by 1000. 250 mL / 1000 = .250 L Third: Plug it into the equation. (0.01136 mol x 0.0821 R x 298 K) / .250 L = 1.1 atm

Which compound name does not correspond to an ionic compound?

Phosphorus pentafluoride

Physical Properties

Physical characteristics Physical behavior Temperature - 0oC for ice water, 100oC for boiling water Mass - A nickle weighs 5 g. A penny weighs 2.5 g. Color - Sulfer is yellow, Bromine is a reddish-brown Taste - Acids are sour. Bases are bitter. Odor - Benzyl acetate smells like jasmine. Hydrogen sulfide smells like rotten eggs. Boiling Point - Water boils at 100oC. Ethyl alcohol boils at 78.5oC. Hardness - Diamond is exceptionally hard. Sodium metal is soft. Density - 1.00 g/mL for water, 19.3 g/cm3 for gold.

Ion Handout

Polyatomic cation NH4 + ammonium ion Polyatomic anions w/-ide ending OH- hydroxide ion w/-ate ending (last element always oxygen) acetate ion nitrate ion carbonate ion sulfate ion phosphate ion ClO3 - chlorate ion* w/-ite ending (last element oxygen, & 1 less O than -ate) nitrite ion SO3 2- sulfite ion* ClO2 - chlorite ion* Polyatomic anions with H at front (charge reduced by 1 for each H) HCO3 - hydrogen carbonate ion

Exponential Numbers

Powers of 10 very small or very large numbers often expressed using exponential notation (scientific notation) - Scientific notation should give a coefficient between 1 and 10 with only one digit before the decimal. - Values smaller than 1 will have negative powers of 10 • Red blood cells have diameter of 0.000006 m or 6 x 10-6 m - Values larger than 10 will have positive powers of 10 • Sun has diameter of 1,400,000,000 m or 1.4 x 109 m

Identify the common indicators that a chemical reaction has occurred.

Precipitate being formed Bubbles being produced A color change A change in temperature

Prefixes in SI System

Prefixes can also be used to indicate units smaller or larger than the base unit.

Match each description to the type of change, physical or chemical.

Propane gas gives off carbon dioxide, water vapor, and heat when it burns in oxygen. - Chemical change A piece of ice that dropped on the floor melted -Physical change Olive oil, vinegar and spices are mixed together to make a salad dressing. - Physical change A puzzle is cut into 500 pieces. - Physical change

Solids, Liquids and Gases

Properties related to spacing and motion of atoms, ions, and molecules: Solids: Highly ordered. The particles of a solid have fixed positions and exhibit motions of vibration. Liquids: Randomly arranged. The particles of a liquid are free to move within the confines of the liquid. Gas: The particles of a gas are far apart and move randomly and rapidly

Gas Properties or Variables

Properties: Units: pressure (P) atm, mmHAG volume (V) mL or L temperature (T) K for calculations number of particles (n) mol for calculations

Summarized his experimental data in 1799 in the law of definite proportions.

Proust

Problem Solving Using Conversion Factors Dimensional Analysis

Quantity(initial unit) x Conversion factor = Equal quantity(new unit) Use conversion factor with desired unit in numerator and given unit in denominator to cancel out given unit. (Quanity (given unit) x CF (desired unit)) / CF (given unit) = New Quantity (desired unit)

Nuclear Equations

Radioactive Isotope = New Isotope + Radiation

Radioisotopes

Radioactivity: spontaneous emission of high energy, or high energy particles, from nucleus of unstable isotope. Radioisotopes - Radioactive isotopes - Unstable isotopes - Undergo nuclear decay (radioactive decay) Radiation emitted from nucleus Changes occur in nucleus

Density (d)

Ratio of quantity of mass(m) per unit volume(V) Density = mass of substance / volume of substance

When any reversible reaction is at equilibrium, what conditions are necessarily true?

Reactants and products are both present in the reaction mixture. The rate of the forward reaction equals the rate of the reverse reaction. The amounts of reactants and products has stopped changing.

Equilibrium Change (shifts)

Reaction will shift to remove anything added. Reaction will shift to replace anything removed. Not in book Shifts: forward, to products, right -> Shifts: reverse, to reactants, left <-

Pressure Gauge

Reading of '0' internal pressure = atmospheric pressure

Millikan's Oil-Drop Experiment

Robert Millikan (1868-1953) an American physicist determined charge on electron in 1909 received 1923 physics Nobel prize

Structure of Atom

Rutherford suggested: - Most mass in nucleus - positive charge in nucleus James Chadwick, English physicist - discovered neutrons in 1932 Nucleus: protons and neutrons - Neutrons have mass but no charge - Very small compared to rest of atom

SI System

Scientists use International System of Units (SI units) - version of metric system - based on decimal system, or powers of 10.

What effect does the removal of NO2- have on the equilibrium for the following reaction? HNO2 + HS - <=> NO2 - + H2S

Shift towards forward reaction to remove stress. (Shift right, products favored).

Nitrogen and hydrogen combine to produce ammonia according to the following reaction. N2 + 3 H2 <=> 2 NH3 What effect does the addition of ammonia have on the equilibrium?

Shift towards reverse reaction to remove stress. (Shift left, reactants favored).

Significant Figures/Digits

Significant Figures/Significant Digits - reported numbers in measurement including est. digit - all digits known with certainty, plus one uncertain digit Counting Significant Figures in measured numbers: - All recorded nonzero digits, including estimated digit, are significant figures (significant digits). - Placeholder zeros are not counted as significant. - Start counting with first nonzero digit and stop at the estimated place

Silicates

Silicate (SiO4) tetrahedron: Si in center with an O at each of four corners. Tetrahedron connect in Chains 1-dimensional Sheets 2-dimensional Crystals 3-dimensional

Mineral Compositio

Silicates - metals with silicon & oxygen Carbonates - metals with carbon & oxygen Oxides - metals with oxygen Sulfides - metals with sulfur

Element

Simplest pure substance Cannot be broken into simpler substance - smaller, yes - more simple compostion, no Composed of one type of atom Atom is smallest characteristic particle 118+ known elements - Not all found in nature

Replacement (Displacement)

Single-Replacement -Element + compound - Element switches place with element in compound Zn (s) + 2 HCl (aq) -> H2 (g) + ZnCl2 (aq) Double-Replacement -Two ionic compounds - Ions rearrange (no new ions formed) Na2SO4 (aq) + BaCl2 (aq) -> BaSO4 (s) + 2 NaCl (aq)

Sublimation is a phase change from ? to ?. The ? phase is not present in this change.

Sublimation is a phase change from solid to gas. The liquid phase is not present in this change.

Soluble

Substance that can be dissolved by the solvent.

Types of Glasses

Soda-Lime Glass - Sodium and Calcium Silicates - Used for Ordinary glass for windows, bottles, other housewares Borosilicate Glass - Boron Oxide (Instead of lime) - Heat Resistant, Used for laboratory ware and ovenware (Pyrex and Kimax) Lead Glass - Lead Oxide (Instead of Lime) - Highly refractive (bends light), Used for optical glass, art glass, table crystal Colored Glass - Selenium Compounds (Ruby Red Glass), Cobalt Compounds (Blue Cobalt Glass), Chromium Compounds (Green), Manganese Compounds (Violet), Carbon and Iron Oxide (Brown Amber Glass) Photochromic Glass - Silver Chloride or Bromide - Darkens when exposed to light, Used for Sunglasses, hospital windows.

Common Bases

Sodium Hydroxide - NaOH - Strong Base Potassium Hydroxide - KOH - Strong Base Lithium Hydroxide - LiOH - Strong Base Calcium Hydroxide - Ca(OH)2 - Strong Base (Not soluble in water) Magnesium Hydroxide - Mg(OH)2 - Strong Base (Not soluble in water) Ammonia - NH3 - Weak Base

Motion & Spacing of Particles

Solid: Takes more energy to pull apart a solid, Particles are close together, it holds the shape Liquid: Particles are a bit spread out but still close together Gas: Particles are spread out as far as they can go

Solubility and Saturated Solutions

Solubility - amount solute dissolved in given amount solvent (usually at a specific temperature) Unsaturated solutions -does not contain the maximum amount of solute. - additional solute will dissolve Saturated solutions - contains the maximum amount of solute. - additional solute does not dissolve, undissolved solute visible Supersaturated solutions - contains more than maximum amount of solute. - not stable, excess dissolved solute eventually separates

Solubility

Soluble: an appreciable quantity dissolves Insoluble: very little, if any, dissolves Dilute solution: little solute in a lot of solvent Concentrated solution: lots of solute in solvent

Concentrated solution

Solution with a large quantity of solute dissolved in a small quantity of solvent.

Dilute solution

Solution with a small quantity of solute dissolved in a large quantity of solvent.

Balance the equation for the reaction of aluminum with phosphoric acid. __ Al +__ H3PO4 → __ H2 + __ AlPO4 Enter the number for the coefficient in the box before the formula for each reactant and product in the equation below. If no number is needed, you will need to enter the 1 for an answer choice. [A] Al + [B] H3PO4 → [C] H2 + [D] AlPO4

Specified Answer for: A 2 Specified Answer for: B 2 Specified Answer for: C 3 Specified Answer for: D 2

Balance the equation for the reaction of iron with sulfuric acid. __ Fe +__ H2SO4 → __ H2 + __ Fe2(SO4)3 Enter the number for the coefficient in the box before the formula for each reactant and product in the equation below. If no number is needed, you will need to enter the 1 for an answer choice. [A] Fe + [B] H2SO4 → [C] H2 + [D] Fe2(SO4)3

Specified Answer for: A 2 Specified Answer for: B 3 Specified Answer for: C 3 Specified Answer for: D 1

Balance the equation for the reaction of Iron(III) oxide reacts with carbon to produce iron and carbon monoxide. __ KO2 + __ CO2 → __ K2CO3 + __ O2 Enter the number for the coefficient in the box before the formula for each reactant and product in the equation below. If no number is needed, you will need to enter the 1 for an answer choice. [A] KO2 + [B] CO2 → [C] H2CO3 + [D] O2

Specified Answer for: A 4 Specified Answer for: B 2 Specified Answer for: C 2 Specified Answer for: D 3

Give the correct atomic symbol for each element. (You should see a box after each name.)

Specified Answer for: antimony - Sb Specified Answer for: zinc - Zn Specified Answer for: vanadium - V Specified Answer for: krypton - Kr Specified Answer for: helium - He Specified Answer for: radium - Ra Specified Answer for: tellurium - Te Specified Answer for: gallium - Ga Specified Answer for: palladium - Pd Specified Answer for: tungsten - W Specified Answer for: uranium - U Specified Answer for: lead - Pb

Electrolysis

Splitting of compounds using electricity Electrolytes conduct electricity Electrodes: carry current - Cathode negatively charged - Anode positively charged Ions: charged particles - Cation positively charged; move toward cathode - Anion negatively charged; move toward anode

Classification of Matter

State or Phase of Matter Substances vs. Mixtures Elements vs. Compounds - Atoms vs. Molecules

Learning Check 2

State the number of significant figures in each of the following measurements. 1. 300 mm 1 2. 4.050 L 4 3. 0.0806 g 3

Electrolytes and Nonelectrolytes

Strong electrolytes - ions present - conduct strong current NaCl (s) (H2O) = Na+ (aq) + Cl- (aq) Weak electrolytes - few ions - both ions and molecules present - conduct weaker current HF (H2O) = H+ (aq) + F- (aq) Nonelectrolytes - only molecules, no ions present C12H22O11 (s) (H2O) = C12H22O11 (aq)

What Is Chemistry?

Study of matter and its changes - Matter: has mass & takes up space

Science and Technology: The Roots of Knowledge

Study of natural/material world has two facets - Technological (Factual), - Philosophical (Theoretical), Technology - practical application of knowledge Natural Philosophy - speculation about nature Alchemy - Mystical chemistry

Substances and Mixtures

Substances (Pure Substance): definite fixed composition composition does not vary from sample to sample either an element or a compound Mixtures: Mixture of two or more substances composition varies from sample to sample composition may vary within sample

Acids & Bases in Industry

Sulfuric acid (H2SO4) is leading chemical substance produced in U.S. Used to manufacture fertilizers and industrial chemicals Is the acid of automotive batteries. Hydrochloric acid: Used as a rust remover Removes lime from mortar and household plumbing fixtures Purchased from hardware stores as muriatic acid. Lime (CaO) is produced by heating limestone (CaCO3). Lime can be slaked by reacting with water to make calcium hydroxide (Ca(OH)2). Slaked lime is used to make mortar and cement and to sweeten soil. Sodium hydroxide is also known as lye: Use as oven cleaner or drain cleaners. Used commercially to make soap. Ammonia: Used as fertilizer and in household cleaning products.

Scientific Laws

Summarize observations or scientific data Universal statement of fact - always true under stated conditions - no known exceptions Sometimes stated as mathematical equation

Suppose you are given the mass of each element in a compound sample. To calculate the empirical formula, start by ? using ? . Then, ? by ?.

Suppose you are given the mass of each element in a compound sample. To calculate the empirical formula, start by converting the mass of each element to moles using each element's molar mass. Then, calculate the ratio between the elements by dividing the moles of each element by the smallest number of moles present.

Suppose you mix two solutions in a test tube and the test tube becomes hot. This is ? because ?.

Suppose you mix two solutions in a test tube and the test tube becomes hot. This is a sign of a chemical reaction because chemical changes can release heat.

Acids, Bases, & Salts

Svante Arrhenius (1859-1927), a Swedish scientist, explained acid and base behavior in 1887. Acids - hydrogen ions in water. HCl (g) (H2O) = H+ (aq) + Cl- (aq) HCl (g) + H2O (l) = H3O+ (aq) + Cl- (aq) Bases - hydroxide ions in water NaOH (s) (H2O) = Na+ (aq) + OH- (aq)

Synthesis & Decomposition

Synthesis: Two or more reactants form single product 2 K + Br2 -> 2 KBr Decomposition: Single reactant producing two or more simpler substances (NH4)2Cr2O7 -> Cr2O3+ N2 + 4 H2O

A reaction that is characteristic of a substance is frequently referred as a ________________.

Test

For each atom, determine how many dots should be drawn around the element symbol in the Lewis structure for a lone, neutral atom.

The Lewis structure of an oxygen atom should have 6 dots drawn around the symbol O. The Lewis structure of a calcium atom should have 2 dots drawn around the symbol Ca. The Lewis structure of a nitrogen atom should have 5 dots drawn around the symbol N. The Lewis structure of an aluminum atom should have 3 dots drawn around the symbol Al. The Lewis structure of a fluorine atom should have 7 dots drawn around the symbol F.

Determine whether each observation generally corresponds to a physical change or a chemical change.

The color of a substance changes over time.: Chemical change A liquid freezes into a solid.: Physical change Bubbles are produced upon mixing two solutions.: Chemical change A solid dissolves into water.: Physical change A precipitate is formed from two solutions.: Chemical change A solution heats up upon mixing with another.: Chemical change

Knowing that one day is 24 hours, how many days is 62.1 hours?

The conversion factor should be made from the equivalence between the two units involved. The conversion factor should be set up so that the units of the starting measurement are on the bottom to cancel and give the new units on top. Then, perform the calculation by multiplying the starting value by the number on top of the conversion factor and dividing by the number on the bottom. 62.1 hours× (1 day / 24 hours) Note that because 24 hours is the definition of a unit, the number is considered infinitely significant and does not affect significant figures.

Knowing that one day is 24 hours and one hour is 60 minutes, how many minutes are in 4.6 days?

The conversion factor should be made from the equivalence between the two units involved. The conversion factor should be set up so that the units of the starting measurement are on the bottom to cancel and give the new units on top. Then, perform the calculation by multiplying the starting value by the number on top of the conversion factor and dividing by the number on the bottom. This conversion requires two conversion factors, one relating days and hours and one relating hours and minutes. 4.6 days× (24 hours / 1 day)× (60 minutes / 1 hour) Note that because 24 and 60 are numbers defining units, the numbers areconsidered infinitely significant and do not affect significant figures in the answer.

The equation to calculate density is ? , where D is the density, m is the ? , and V is the ?.

The equation to calculate density is D=m/V, where D is the density, m is the mass, and V is the volume.

Which statement is true about a chemical reaction at equilibrium?

The forward reaction rate is equal to the reverse reaction rate.

Buffers in the Blood

The normal pH of blood is between 7.35-7.45 CO2 + H2O H2CO3 (H2O) = H3O+ + HCO3- Acidosis - is a condition in which there is too much acid in the body fluids. Alkalosis - a condition in which there is too much base in the body fluids

A sample of gas is subject to changes in conditions. Predict the effect of each change.

The pressure and volume are increased. What will happen to the temperature?: It will increase. The pressure and the temperature are both decreased by 50%. What will happen to the volume?: It will stay the same. The pressure is kept constant, while the temperature is decreased. What will happen to the volume?: It will decrease. The volume and temperature remain constant, while some of the gas is let out of the container. What will happen to the pressure?: It will decrease.

Determine whether the given ionic formula for each named compound is correct or not.

Titanium(IV) iodide: TiI4: Correct formula Aluminum selenide: Al3Se2: Incorrect formula Ruthenium(IV) oxide: Ru2O4: Incorrect formula Barium sulfide: BaS: Correct formula

To measure out a volume of liquid, start by choosing the appropriate graduated cylinder and moving the bumper to the ? of the graduated cylinder to protect it from breakage. Then, pour the liquid into the graduated cylinder until the ? of the meniscus aligns with the desired volume marking when you look at the graduated cylinder from ?

To measure out a volume of liquid, start by choosing the appropriate graduated cylinder and moving the bumper to the top of the graduated cylinder to protect it from breakage. Then, pour the liquid into the graduated cylinder until the bottom of the meniscus aligns with the desired volume marking when you look at the graduated cylinder from eye level.

In lab, you may need to evaluate the odor or smell of a chemical. What is the best way to smell a chemical sample?

Use your hand to gently waft the smell toward you.

Determine whether each of the properties described applies to volumetric or graduated glassware.

Used for applications in which great accuracy is needed: volumetric Capable of measuring a range of volumes of liquid: graduated Designed to measure one specific volume of liquid: volumetric

A sample of gas at a temperature of 400 K has a volume of 3.00 L. At what temperature would the volume of the gas be 3.75 L if the amount and pressure of the sample remain constant?

V1 / T1 = V2 / T2 3L / 400 K= 3.75L / ? 3L / (400 K x 3.75 L) = 500 K

Predicting Shapes of Molecules

VSEPR - How many bonding regions of electrons Count double or triple bond as one region Or Count number atoms attached - How many lone pairs (nonbonding regions) - Spread out as far as possible

Valence Electrons Definition

Valence electrons - electrons in outermost shell

Outer Electron Configurations

Valence electrons - electrons in outermost shell Elements in same group (column) have same number valence electrons Examples - Alkali metals: - Alkaline earth metals: - Halogens: - Noble Gases: Outer Electron Configurations 1 valence electron 2 valence electrons 7 valence electrons 8 valence electrons only 2 for Helium

The composition of heterogeneous mixtures is ______________.

Variable

Standard Molar Volume

Volume occupied by 1 mol of gas at Standard temperature and pressure (STP) - 1 atm pressure and 0°C (273K) - 1 mole of gas at STP has volume of 22.4 L

Water (and in aqueous solutions)

Water can act like a weak acid or a weak base H2O + H2O = H3O+ + OH- Pure water is neutral. [H3O+] = [OH-] = 1x10^-7 M

Line Spectrum

When light from a gaseous substance is passed through a prism, it produces a line spectrum. Light from element - colored lines (sometimes IR or UV)

When performing a multiplication or division calculation, significant figures in the calculated result are dictated by the ? of the measured numbers. The calculated result should have ? the measured number in the calculation with the fewest ?.

When performing a multiplication or division calculation, significant figures in the calculated result are dictated by the significant figures of the measured numbers. The calculated result should have the same number of significant figures as the measured number in the calculation with the fewest significant figures.

When sodium chloride, NaCl, dissolves in water, the solution contains ? in addition to the water solvent. The partial charges in water help dissolve the compound as the hydrogen end of water is attracted to the ? and the oxygen end is attracted to the ?.

When sodium chloride, NaCl , dissolves in water, the solution contains sodium ions and chloride ions in addition to the water solvent. The partial charges in water help dissolve the compound as the hydrogen end of water is attracted to the chloride ion and the oxygen end is attracted to the sodium ion.

Le Chatelier's Principle

When stress applied to equilibrium system, reaction shifts to relieve stress. Stress may include: temperature changes addition of reactants or products removal of reactants or products

When using the Tare function on a balance, start by ? Then, ? to cancel out that mass. Finally, ? and record the mass of your sample.

When using the Tare function on a balance, start by placing the glassware on the balance. Then, press the Tare/Zero button to cancel out that mass. Finally, add your sample to the glassware and record the mass of your sample.

Naming Practice: Ionic Compounds

When writing names do not forget (RN) if required. Determine (RN) by calculating ionic charge needed to balance negative charge in compound. Can you name these ionic compounds? CdSe - Cadmium Selenide AuBr3 - Gold (III) Bromide

Cathode Ray Tube

William Crookes(1832-1919), an English chemist Passed current through tube at low pressure

Table 12.3 Some Silicate Minerals

Zirconium Silicate - Simple Anion (SiO4^4-) - ZrSiO4 - Used for Ceramics; Gemstones (Zircon) Spodumene - Long Chains of SiO4 - LiAl(SiO3)2 - Source of Lithium and its compounds Chrysotile Asbestos - Double Chains of SiO4- Mg3(Si2O3)(OH)4 - Used for Fireproofing (Now banned) Muscovite Mica - Sheets of SiO4 - KAl2(AlSi3O10)(OH)4 - Used for Insulations; lustrous paints; packing (vermiculite) Quartz - Three-Dimensional Array of SiO4 - SiO2 - Used for Making glass (Sand); gemstones (amethyst, agate, citrine)

Which one of these elements is a halogen?

bromine

A mixture of clay, lime, and water that hardens like stone when it dries is called

cement

Hard, porous inorganic material made by firing clay and other minerals at high enough temperatures to partially melt and fuse the minerals is called

ceramic

The element with the abbreviated electron configuration of [Ne] 3s2 3p5 is

chlorine

Which of the following elements should have the highest electronegativity?

chlorine

Which one of these elements is an nonmetal?

chlorine

Atoms of which of the following elements have a nucleus with 24 protons?

chromium

This reaction is an example of which type of chemical reaction? 2 C8H18 + 25 O2 → 16 CO2 + 18 H2O

combustion (burning)

Rutherford's Experiment and Model Explaining Rutherford's Experiment

conclusion: atoms have positively charged nucleus.

Ionic Compound Formula

indicates which ions present also indicates how many of each ion - subscript included if number ions is greater than one cation first, anion last sum of ion charges equals zero (or + & - cancel) - charges not shown in compound formula. - If you do not know charges of ions you won't be able to determine the formula subscripts. 5 Ionic Formula Example: Ca3(PO4)2 3 calcium ions 2 phosphate ion Only use ( ) around polyatomic ions if more than 1 present 3 (+2) + 2 (-3) = 0

The substance that changes color in the presence of an acid or a base is a(n)

indicator

Substances with carbonate ions, CO32-, react with acids to ______________.

liberate carbon dioxide

The reaction between chloride salts and concentrated sulfur acid __________________.

liberates hydrogen chloride

Temperature

measures intensity of heat measures how hot or cold an object is average kinetic energy of an object. SI unit is Kelvin (K) - Absolute temperature scale - No negative numbers - O K = - 273 oC - To determine K K = oC + 273

The standard base metric unit for length measurements is the

meter

Which of the following is the correct IUPAC name for the compound MoF6 ?

molybdenum(VI) fluoride

The elements xenon, neon, and radon are ________

noble gases

Sucrose is biomolecule that is water soluble. Sucrose does not give ions in solution. Which of the following would best classify a solution of sucrose?

nonelectrolyte

Elements which are generally dull in appearance and are poor conductors of heat or electricity are called

nonmetals

Examples of Significant Digits/Figures

nonzero digits. 52.571 g has 5 s.f. zero between nonzero digits. 30.5 mL has 3 s.f. zero at End of decimal number. 24.0 cm has 3 s.f. Do NOT count Placeholder zero. 0.071 kg has 2 s.f. 52,500 mg has 3 s.f. 0.2350 L has 4 s.f.

Type of nuclear reaction when small nuclei combine to form a larger nucleus is called

nuclear fusion

Atoms of an element in a compound lose, gain, or share valence electrons in order to produce a stable, noble gas arrangement of electrons. This statement refers to the

octet rule

Chemical Symbols

one or two letter abbreviation for element first letter always capitalized second letter, if one, always lower case Oxygen - O Lithium - Li Copper (from Latin, cuprum) -Cu Iron (from Latin, ferrum) - Fe

Which gas is a required reactant for a combustion reaction?

oxygen

Acid Rain

pH below 5.6 Carbon dioxide (CO2), sulfur dioxide (SO2), nitrogen monoxide (NO), and nitrogen dioxide (NO2) are major nonmetallic oxides responsible for acid rain formation. SO2 + H2O = H2SO3 Example of an acid forming.

When several drops of an NaOH(aq) are added to a buffer system, what happens to the pH of the buffer?

pH stays the same

Mixtures

physical blend of two or more substances. Homogeneous mixtures appear uniform in composition. Heterogeneous mixtures are not uniform in composition.

Stoichiometry

quantitative relationship between reactants and products in a balanced chemical equation The coefficients of a balanced chemical equation represent moles.

The starting materials in a chemical reaction are called

reactants

Intermolecular Forces in Solutions

solution - homogeneous mixture - solute dissolved in solvent Solute: substance dispersed in solution. Solvent: substance doing dissolving, usually the greater quantity

An alloy of iron and carbon is called

steel

Potential energy is

stored energy

The correct name for SO2 is

sulfur dioxide