Chemistry 1210 OSU Final
How to set up a dimensional analysis equation
(Given Unit / 1 ) X (desire unit / given unit ) = desired unit
other halogens have an oxidation number of _________ in most binary compounds.
-1 Exception: When combined with oxygen, as in oxyanions, however, they have positive oxidation states.
Examples of exact numbers
-12 eggs in a dozen -1000 g in 1 kg -Exactly 2.54 cm in an inch -The number 1 in any conversion factor ex 1 m = 100 cm or 1 kg = 2.2046 lb -Counting objects
what is the oxidation number of S^2-
-2
The oxidation number of oxygen is usually _______ in both ionic and molecular compounds.
-2 Exception: peroxides, which contain the O2^2- ion, giving each oxygen an oxidation number of −1.
Nonmetallic elements aka nonmetals
-Elements in the upper right corner of the periodic table -differ from metals in their physical and chemical properties -can be gas or solid (one liquid)
Strong acids
-HCl -HBr -HI -HClO3 -HClO4 -HNO3 -H2SO4
Strong bases
-LiOH -NaOH -KOH -RbOH -CsOH -Ca(OH)2 -Sr(OH)2 -Ba(OH)2
How to find the sig fig
-Read the number from left to right -Counting digit starting with the first digit that is not zero -All nonzero digits are significant
How to from multi step molarity problems
-grams of A----> moles of A -moles A-----> moles of B -moles of B / molarity of B= volume of B or -moles B / volume of B= molarity
Calorie to Joule equation
1 cal = 4.184 J
1 mL is the same volume as...
1 cm^3
Which has a greater density 1 kg of air or 1 kg of iron?
1 kg of iron because it occupies a smaller volume while weighing the same amount
how to do combustion analysis
1. Convert CO2 grams into grams of C 2. Convert H2O grams into grams of H 3. Add grams of C and H and subtract it from the mass of the sample to get grams of oxygen 4. Convert C, H, and O to moles 5. Use the smallest mole amount to divide all the moles including the one used 4.If not an exact number multiple all numbers until it is (Ex: 1:1.5:1 has be multiplied by 2 and we get empirical formula of 2:3:2)
How to find a derived unit
1. Define the equation for quantity 2. Substitute the appropriate base units Ex speed is the ratio of distance traveled to elapsed time. So the derived SI unit for speed is the SI unit of distance -length (m) - divided by the SI unit for time - sec - which gives m/s or meters per second
Dalton's atomic theory
1. Each element is composed of extremely small particles called atoms 2. All atoms of a given element are identical but the atoms of one element are different from the atoms of all other elements 3. Atoms of one element cannot be changed into atoms of a different element by chemical reactions. Atoms are neither created nor destroyed and chemical reactions 4. Compounds are formed when atoms of more than one element combine. A given compound always has the same relative number and kind of atoms
Naming binary (two-element) molecular compounds
1. The name of the element farther to the left in the periodic table (closest to the metals) is usually written first. An exception occurs when the compound contains oxygen and chlorine, bromine or iodine (any halogen except fluorine) in which case oxygen is written last 2. If both elements are in the same group, the one closer to the bottom of the periodic table is named first 3. The name of the second element is given an -ide ending 4. Add Greek prefixes to indicate the number of atoms of each element Exceptions: 1. the prefix mono- is never used with the first element 2. When the prefix ends in A or O and the name of the second element begins with a vowel, the a or o of the prefix is often dropped
How to find empirical formula from percent composition
1. make the percentage given into grams (74.2%= 74.2g) 2.determine the moles by using molar mass 3. Using the smaller mole divide the other moles calculated including the one used 4.If not an exact number multiple all numbers until it is (Ex: 1:1.333:1 has be multiplied by 3 and we get empirical formula of 3:4:3)
How to make a BCA chart
1. write the balanced equation 2. convert the moles or reactants to mole of desired product, which ever is the smallest is the limiting reactant 3. use the moles of limiting reactant and stoichiometric equivalence to get moles used by excess reactant 4. subtract amount the excess reactants initial amount of moles from moles used to get amount of excess left
Density of water
1.00 g/cm^3 aka 1.00g/mL
The magnitude of kinetic energy
1/2mv^2 *as velocity or mass increases so does KE
Room temperature in Celsius
25 degrees Celsius
How to find # of Cu atoms in 3g of Cu
3g Cu x (1 mol Cu/63.5 g Cu) x (6.02 x 10^23 atoms/1 mol Cu)= 3x10^22
Avogadro's number
6.02 x 10^23
Using stoichiometric equivalence to find grams of CO2 from grams of C4H10
8 mol CO2= 2 mol C4H10 1.00g C4H10 x (1 mol/58.0 g C4H10) x (8 mol CO2/2 mol C4H10) x (44.0g CO2/ 1 mol CO2)= 3.03g CO2
periodic table
A chart of all chemical elements currently known, organized by their properties.
Molecular formula
A chemical formula that indicates the actual number of atoms in each element in one molecule of a substance Ex CH4 H2O
Empirical formula
A chemical formula that shows the kinds of atoms and their relative numbers in a substance in the smallest possible whole number ratios
redox reaction
A chemical reaction involving the transfer of one or more electrons from one reactant to another; also called oxidation-reduction reaction.
Angstrom
A common non-S I unit of length that is used to measure atomic dimensions 1A = 10^-10m
Ionic compound
A compound composed of cations and anions
Naming polyatomic ions with -ide
A few polyatomic anions also have names ending in -ide Ex OH^- hydroxide ion Ex CN^- cyanide ion Ex Osub2^2- peroxide ion
Structural formula
A formula that shows not only the number and kinds of atoms in the molecule but also the arrangement of the atoms
Conversion factor
A fraction whose numerator and denominator are the same quantity expressed in different units
Solvent
A liquid substance capable of dissolving other substances
Precision
A measure of how closely individual measurements agree with one another
Mass (Kg)
A measure of the amount of material in an object
Temperature
A measure of the hotness or coldness of an object It is a physical property that determines the direction of heat flow
dimensional analysis
A method of problem-solving in which units are multiplied together or divided into each other along the numerical values Ensures that the final answer of a calculation has the desired units
Perspective drawings
A model that uses wedges and dashed lines to depict bonds that are not in the plane of the paper. Crude 3-D shape
Diatomic molecule
A molecule consisting of two atoms Ex: H2, O2, N2, F2, Cl2, Br2, and I2
Anion
A negatively charged ion
Electrons
A negatively charged subatomic particle found outside the atomic nucleus. It is a part of all atoms. Aka CATHODE RAYS
Chemical formula
A notation that uses chemical symbols with numeric subscripts to convey the relative proportions of atoms of the different elements in a substance
Oxyanions
A polyatomic anion that contains one or more oxygen atoms
Oxidative number
A positive or negative whole number assigned to an element in a molecule or ion on the basis of a set of formal rules
Cations
A positively charged ions
Proton
A positively charged subatomic particle found in the nucleus of an atom
Distillation
A process that depends on the different abilities of substances to form gases Used in homogeneous mixtures
Filtration
A process that uses a porous barrier to separate materials based on the size of their particles.
metathesis reaction
A reaction in which two substances react through an exchange of their ions Ex:Ax+bY ---> AY+by
standard solution
A solution of know concentration
Scientific law
A statement of what is always observe to happen to the best of our knowledge
Heat spontaneously flows from...
A substance at a higher temperature to one at a lower temperature High to Low
nonelectrolyte
A substance that dissolves in water but does not contain ions and does not conduct an electric current
Solute
A substance that is dissolved in a solvent to form a solution.
Acid
A substance whose molecules yield hydrogen ions (H^+) when dissolved in water
The Celsius Scale
A temperature scale on which water freezes at 0 and boils at 100 at sea level
Theory
A tested model or explanation that has predictive powers and that accounts for all available observations
Atomic mass unit
A unit based on exactly 12 amu for the mass of the isotope of carbon that has six protons and six neutrons in the nucleus 1 amu = 1.66054 x 10^-24 g
Calorie
A unit of energy It is equal to the amount of energy needed to raise the temperature of 1 g of water by 1°C from 14.5 C to 15.5 C
How to name and formulate a cation ionic compound
A. Cations formed from metal atoms have the same name as the metal B. If a metal can form cations with DIFFERENT CHARGES, the positive charge is indicated by a Roman numeral in parentheses following the name of the metal
How to write an acid formula
Acids are always written with an H as the first element Ex HCl Ex H2SO4
Dilution
Adding water to a solution in order to decrease the concentration
What is the SI unit used for electric current?
Ampere (A or amp)
Derived Unit
An S I unit obtained by multiplication or division of one or more of the SI base units
Electrolyte
An aqueous solution that contains ions and conducts an electric current
Ion
An atom that has had its electrons removed or added so that it has a electrical charge Ions can be positively or negatively charged depending on whether electrons are lost (positive) or gained (negative) by the afoms
Neutron
An electrically NEUTRAL particle found in the nucleus of an atom.. it has approximately the same mass as a proton.
Polyatomic ion
An electrically charged group of two or more atoms Ex:NH4^+
Mass spectrometer
An instrument used to measure the precise masses and relative amounts and mixtures of substances
salt
An ionic compound made from the neutralization of an acid with a base. -it is aqueous
Composition of an acid
Anion connected to enough H+ ions to neutralize (balance) the anions charge Ex SO4^2- ion requires two H^+ ions , forming H2SO4
Property
Any Characteristic That Can Be Used To Identify a particular type of matter and distinguish it from other types
Changes of state
Any change from liquid gas or solid is a physical change
Inorganic compound
Any compound not containing carbon and hydrogen
Examples of inexact numbers
Any number obtained by measurement Any measurement obtained by equipment has inherent limitations and errors Human errors Physical surroundings vary
Elements
Any substance that cannot be broken down into simpler substances
Matter
Anything that has mass and takes up space
Structure
Arrangement of atoms
Quantitative
Associated with numbers
Qualitative
Associated with quality as in size appearance value etc
Submicroscopic
Atoms and molecules
Isotope
Atoms of the same element containing same number of protons but different numbers of neutrons and therefore having different masses
Chemical energy is consumed when
Bonds between atoms are broken
Chemical energy is released when...
Bonds between atoms are formed
What is an Atom?
Building blocks of matter (singular)
Alkane with four carbons
Butane
What is the empirical formula of C2H4?
CH2
A combustion reaction between a hydrocarbon and oxygen form...
CO2 and H2O
Capital C Calorie vs c calorie
Calorie (note the capital C) is 1000 times larger than a calorie 1 Cal = 1000 cal = 1 kcal
What is the SI unit used for luminous intensity?
Candela (cd)
The -ium ending
Cations formed from molecules composed of NONMETAL atoms have names that end in -ium Ex NH4^+ ammonium ion Ex H3O^+ hydronium ion
Naming an acid containing an anion that ends in -ate or -ite
Change -ate to -ic Change -ite to -ous Then add the word acid
Naming an acid containing an anion that ends in -ide
Change the -ide to -ic and add the prefix hydro- and follow with the word acid Ex Cl^- chloride becomes HCl hydrochloric acid Ex S^2- sulfide becomes H2S hydrosulfuric acid
Ions of the same element that have different charges have different....
Chemical and physical properties
Name the acid HClO2
Chlorous acid
What is the first step of the scientific method?
Collect information via observations of natural phenomena and experiments
How to know charges of ions
Column number for metals= charge Column number for nonmetal-8=charge
Mixtures
Combinations of two or more substances in which each substance retains its chemical identity
Isomer
Compound whose molecules have the same overall composition but different structures Ex 1-propanol and 2-propanol are structural isomers that have the same molecular formula but different structures
Hydrocarbon
Compounds composed of only carbon and hydrogen
Alcohol
Compounds of carbon and hydrogen containing only carbon-carbon single bonds Obtained by replacing an H atom of an alkane with an -OH group Name dervived from alkane but end in -ol
Alkanes
Compounds of carbon and hydrogen containing only carbon-carbon single bonds (it's a hydrocarbon)
Structural isomers
Compounds that have the same molecular formula but different structural formulas
Organic compounds
Contain carbon and hydrogen, often in combination with oxygen nitrogen or other elements
Electrolysis
Decompose water (compound) into its basic elements hydrogen and oxygen by passing an electrical current through it 11% hydrogen and 89% oxygen
Fahrenheit to Celsius equation
DegreeC= 5/9 (F-32)
Celsius to Fahrenheit equation
DegreeF = 9/5 (C) + 32
Temperature should always be specified when reporting...
Density (if not we assume 25 C)
Density equation
Density = mass / volume
How to find density with mass and volume
Density = mass / volume
Extensive properties
Depend on the amount of sample Ex depend on mass or volume
Potential energy
Determined by the position of an object relative to other objects "Stored energy" that arises from the attractions and repulsiones an object experiences in relation to other objects
Methods of Separating mixtures
Dissolving Magnet Filtration Distillation Column chromatography
Intensive properties
Do not depend on the amount of a sample being examined Can be used to identify substances Ex: Temp, melting point, and density
Naming alkanes
Each alkane has a name that ends in -ane Ex C8H18 is octane
What are the compositions of matter?
Element, compound, or mixture
Groups
Elements that are in the same column of the periodic table Elements within the same group or family exhibit similarities in their chemical behavior
Metallic elements aka metals
Elements that are usually solids at room temperature, exhibit high electrical and heat conductivity, and appear lustrous. Most of the elements in the periodic table are metals
Metalliods
Elements that lie along the diagonal line separating the metals from the non-metals in the periodic table The properties of the metalloides are intermediate between those of metals and nonmetals
Transition metals
Elements that occur in the middle of the periodic table Commonly form cations with different charges
Naming polyatomic anions containing oxygen (oxyanions)
End in either -ate or -ite and are called oxyanions Ex NO3^- nitrate ion Ex NO2^- nitrite ion Ex SO4^2- sulfate ion Ex SO3^2- sulfite ion
who discovered the proton?
Ernest Rutherford
Who disproved the plum pudding model?
Ernest Rutherford therefore JJ had beef with him
Atoms differing in number of neutrons
Ex 12/6C reads carbon-12 6 protons and 6 neutrons VS carbon atoms that have 6 protons and 8 neutrons has mass number 14
How to set up a dimensional analysis equation with multiple conversion factors
Ex speed in mi/hr = (515 m/s) ( 1 km/ 10^3 m) (1 mi / 1.6093 km) (60s/1 min) (60 min/1 hr)= 1.15 x 10^3 mi/hr
What are the two types of numbers encountered in scientific work?
Exact numbers and inexact numbers
Electrostatic potential energy
Form of potential energy which arises from the interactions between charged particles I.e. Opposites attract vs same charge repels Strength increases as the magnitude of the charge increases and decreases as the distance between charges increases
What is the second step of the scientific method?
Formulate a hypothesis
What is the fourth step of the scientific method?
Formulate a theory based on the most successful hypotheses
Giga
G=10^9
States of matter
Gas solid or liquid
What are the physical states?
Gas, solid, or liquid
Metals that form only 1 cation (only one possible charge)
Group 1A 2A and Al3+ (group 3A) and two transition metal ions: Ag^+ (group 1B) and Zn^2+ (group 2B)
What is the empirical formula of H2O?
H2O
What is the empirical formula of H2O2?
HO
Rank the acid from weakest to strongest
HX,HZ,HY
Solid
Has a definite shape and volume and is not compressible to any appreciable extent
Solution
Homogeneous mixture
The law of multiple proportions
If two elements A and B combine to form more than one compound, the masses of B that can combine with a given mass of A are in the ratio of small whole numbers (review)
The law of constant composition
In a given compound, the relative numbers and kinds of atoms are constant
The prefix hypo-
Indicates one O atom fewer than the oxyanion ending in -ite Ex ClO2^- chlorite ion (one O atom fewer than chlorate) Ex ClO^- hypochlorite ion (one O atom fewer than chlorite)
The prefix per-
Indicates one or more O atom than the oxyanion ending in -ate Ex ClO4^- perchlorate ion (one more O atom than chlorate) Ex ClO3^- chlorate ion
If a result contains more than the correct number of significant figures...
It must be rounded off
How was the electron discovered?
JJ Thomson completed the cathode ray experiment. Saw that the cathode had a stream of negatively charged particles by using charged plates to bend the stream. The ray avoided the negative plate. Concluded there must be a negative particle. Called it the electron.
Who discovered the neutron?
James Chadwick
Celsius to Kelvin equation
K= degreeC + 273.15
What is the SI unit used for temperature?
Kelvin (K)
What is the SI unit used for mass?
Kilogram (Kg)
The 7 SI units
Length Mass Temperature Time Amount of substance Electric current Luminous intensity
Volume of a cube
Length^3
dilution formula
M1V1=M2V2
Mega
M=10^6
How to find mass with volume and density
Mass = Volume x Density
The magnitude of kinetic energy depends on
Mass and velocity (speed)
Pure substance
Matter that has distinct properties and a composition that does not vary from sample to sample
Milikans Oil Drop Experiment
Measured the charge of the electron. Small drops of oil are allowed to fall between electrically charged plates. Millikan measured how varying the voltage between the plates affected the rate of fall. From these data he calculated the negative charge on the drops. Because the charge on any drop was always some interval multiple of 1.602 x 10^-19 C, Millikan deduced this value to be the charge of a single electron. The force of gravity pulls drops down word but is a post by the electric field that pushes the negatively charged drops upward.
The elements of the periodic table are mostly...
Metals
What is the SI unit used for length?
Meter (m)
Simple organic molecules
Meth = 1 Eth = 2 Prop = 3 But = 4 I.e. Methane Butane Propane
Column chromatography
Mixture is separated by dissolving in a solvent Put components in a pipet/buret? Components separately solvent is added throughout the process. Each component is collected as it reaches the bottom of the column
Homogeneous
Mixtures that are uniform throughout have few compounds Aka solutions
Heterogenous
Mixtures that do not have the same composition and properties or appearance throughout In general, vary in texture and appearance in one sample Have many compounds
Nuclear model
Model of the atom with a very small and extremely dense nucleus containing most of the mass (protons and neutrons) and with electrons in the space outside the nucleus. Further most of the atom is empty space with electrons moving around the nucleus
Ball and stick models
Model that depicts atoms as spheres and bonds as sticks. Accurately represents angles
Space filling models
Model that shows relative size of the atoms - smooshed balls of color coded molecules
What is the SI unit used for the amount of a substance?
Mole (Mol)
How do we find the whole-number multiple?
Molecular weight/ empirical weight
Why is density temperature dependent?
Most substances volumes change if they are heated or cooled
Nano
N= 10^-9
Weak base
NH3
Is a measurement from a pipette exact?
NO because any measurement is inexact!
Would PbI2(s) be consider an electrolyte?
NO! its not a water soluble ionic compound
Which weighs more 1 kg of air or 1 kg of iron?
Neither they both have the same MASS!
Is O^2- a polyatomic ion?
No
will a reaction occur if Ag(s) is combined with MgNO3?
No because Mg^2+ is not a very reactive ION -higher on the reactivity series
Is a weak acid a strong electrolyte?
No but a strong acid is
Gas aka vapor
No fixed volume or shape; rather, it uniformly fills its container Can be compressed into small space or expand to occupy larger one
is millimeters a derived unit?
No its just a normal measurement
Do the number of protons in atom ever differ?
No only neutrons and electrons differ
What happens if all the ions in a complete ionic equation are spectator ions?
No reaction occurred
Can theory be proven absolutely true?
No, however, we treat it as it is true until disproven
Most stable group on the periodic table is..
Noble gases
Do isomers have the same molecular formula?
Not always
Physical properties
Observed without changing the identity and composition of the substance Ex: color, odor, density, melting point, boiling point, and hardness
Oil floats on water because
Oil is less dense than water because the molecules that make up oil are larger so they can not pack together as tightly as water so they take up more space and are more dense
Macroscopic
Ordinary sized objects
Functional groups
Other classes of organic compounds that are obtained when one or more hydrogen atoms in an alkanes is replaced with a specific group of atoms Ex alcohol
Pico
P= 10^-12
Subatomic particles
Particles such as protons neutrons and electrons that are smaller than an atom
is temperature chemical or physical property?
Physical property
Matter is classified by
Physical state and composition
Radioactivity
Possessing radioactivity; the spontaneous disintegration of an unstable atomic nucleus with accompanying emission of radiation
what are examples of metathesis reactions?
Precipitate reactions and acid-base neutralization reactions
Compounds
Pure substances that are the chemical bond of two or more elements.
precipitate reaction
Reactions that result in the formation of an insoluble product
Accuracy
Refers to how closely individual measurements agree with the correct or true value
What is the fifth step of the scientific method?
Repeatedly test theory and modify as needed to match experimental results or reject
Who discovered the charge of an electron?
Robert Millikan
Who is know for the nuclear model?
Rutherford
What is the SI unit used for time?
Second (s or sec)
The denser liquid will...
Sink to the bottom and the less dense liquid will float on top
Cathode rays
Streams of electrons that are produced when a high voltage is applied to electrodes in an evacuated tube. Cathode rays are the radiation produced between electrodes. Cathode rays originate at the negative electrode and traveled to the positive electrode
Physical change
Substance changes physical appearance but not it's composition Ex changes of state
Element
Substances that can not be decomposed into smaller substances Each element is composed of only one kind of atom
Hypothesis
Tentative explanation of a series of observations First step of scientific method
What is the third step of the scientific method?
Test the hypothesis via experiments
The Kelvin scale
The SI temperature scale 0 K = -273.15 degrees C
Joule (J)
The SI unit for energy
Energy
The ability to do work or transfer heat
Solubility
The amount of a substance that dissolves in a given quantity of a solvent at given temperature to form a saturated solution
What is density?
The amount of mass in a unit volume of a substance
Periodic table
The arrangement of elements in order of increasing atomic number with elements having similar properties placed in vertical columns
Atomic weight
The average mass of the atoms of a element in atomic mass units. It is numerically equal to the mass in grams of one mole of the element *Listed on periodic table
What is solvation?
The clustering of solvent molecules around a solute particle. It prevents cation and anion from recombining and stabilize the ions
Significant figures
The digits that indicate the precision with which a measurement is made All digits of a measured quantity are significant, including the last digit, which is UNCERTAIN
Kinetic energy
The energy of motion
Work
The energy transferred when a force exerted on an object causes the displacement of that object
Heat
The energy used to cause the temperature of an object to increase
Scientific method
The general process of advancing scientific knowledge by making experimental observations and by formulating hypotheses theories and laws
Composition
The kinds of atoms the matter contains
-ide ending of anions
The names of monatomic anions are formed by replacing the ending of the name of the element with -ide Ex H^- hydride ion Ex O^2- oxide ion Ex N3^- nitride ion
Electronic charge
The negative charge carried by an electron. It has a magnitude of 1.602 x 10^-19 C
Atomic number
The number of protons in the nucleus of an atom of an element
Law of definite proportions
The observation that the elemental composition of a compound is always the same Same as law of constant composition
Law of constant composition
The observation that the elemental composition of a compound is always the same. Same as law of definite proportions
When naming a binary compound, if both elements are in the same group...
The one closer to the bottom of the periodic table is named first and the second element is given an -ide ending
SI Units
The preferred metric units for use in science. Has seven base units.
Plum pudding model
The proposition that an Adam consists of a uniform positive spirit of matter in which the mass is evenly distributed and in which the electrons are embedded like raisins in a pudding or seeds in a watermelon
Sig Fig Multiplication and Division Rule
The results contain The same number of significant figures as the measurement with the fewest SIGNIFICANT FIGURES Ex length 6.221 cm x width 5.2 cm = 32.3492 cm^2 round to fewest sig figs (2) = 32
Sig Fig Addition and Subtraction Rule
The results should have the same number of decimal places as the measurement with the fewest DECIMAL PLACES Ex 20.42 + 1.322 + 83.1 = 104.842 round to one decimal place = 104.8
Periods
The row of elements that lie in a horizontal row in the periodic table
Atom
The smallest representative particle of an element The almost infinitesimally small building block of matter
Organic chemistry
The study of carbon containing compounds, typically containing carbon-carbon bonds
Component
The substances that make up a mixture
Mass number
The sum of the number of protons and neutrons in the nucleus of a particular atom
The law of conservation of mass
The total mass of materials present after a chemical reaction is the same as the total mass present before the reaction
Metric system
The units used for scientific measurements
Chemical properties
The way a substance may change or react to form other substances Ex: flammability
What do graduated cylinders, syringes, and burettes have in common?
They are used to deliver VARIABLE volumes
Exact number
Those whose values are known exactly Can result from counting objects
Inexact numbers
Those whose values have some uncertainty Any number obtained by measurement is inexact
What is a pipette used for?
To deliver a SPECIFIC volume
What is a volumetric flask used for
To hold a SPECIFIC volume
Transfer of heat is simply
Transfer of kinetic energy at the molecular level bc atoms and molecules gain kinetic energy and average speed increases when they are heated
Chemical change
Transformed into a substance that is chemically different from the original substance
Is this statement true or false: Whenever one substance is oxidized, another substance must be reduced.
True
What is a molecule?
Two or more atoms joined in specific shapes (can be a compound).
The last digit reported for any measured quantity is always...
Uncertain
Liter
Unit of volume 1000 mL= 1 L
Sig Fig Exponential notation
Used to indicate which zeros are insignificant 1.03 x 10^4 g has 3 sig Fig 1.030 x 10^4 g has 4 sig Fig 1.0300 x 10^4 g has 5 sig Fig
Nucleus
Very small very dense positively charged portion of an atom composed of protons and neutrons
Formula of work
W= F x d Where F is force and D is the distance that it moves
How do we know if metal will be oxidized?
We use the activity series
Rutherford scattering experiment
When alpha particles pass through a gold foil most pass-through undeflected but some are scattered, a few at very large angles. This contradicted the plum pudding model which said particles should experience only very minor deflections. The nuclear model of the atom explains why a few particles are deflected at large angles. Most of the space around the nucleus contains only low mass electrons
When is oxygen written last
When you are naming a two-element compound that contains oxygen and chlorine, bromine, or iodine (any Halogen except fluorine)
Is a joule a derived unit?
YEAH, 1 J = 1 kg-m^2/s^2 this can be seen from kinetic energy equation which is KE= 1/2 mv^2 m= kg v^2= (m/s)^2
is the actual yield always less than the theoretical?
YES
Are potential energy and kinetic energy interconveritable?
Yes
Is SO4^2- a polyatomic ion?
Yes
Is a strong base a strong electrolyte?
Yes
will a reaction occur if Mg(s) is combined with AgNO3?
Yes because Ag^+ is a very reactive ion -lower on the reactivity series
Is density a derived unit?
Yes because of its formula mass/volume= density
Are all water solube ionic compounds strong electrolytes?
Yes because they always dissociate if they are aqueous
Are most molecular compounds nonelectrolytes?
Yes but acids are an exception
Can empirical and molecular formulas be the same
Yes if the formula is already in it's simplest form
Do most elements occur in nature as a mixture of isotopes?
Yes to find there mass we use the atomic weight formula
Are spectator ion cancelled out in net ionic equations?
Yes!
Are strong bases water soluble ionic compounds?
Yes!
Sig Fig Zero Rule 2
Zeros at the beginning of a number are never significant - they merely indicate the position of the decimal point Ex 0.02 g has 1 sig Fig Ex 0.0026 cm has 2 sig Fig
Sig Fig Zero Rule 3
Zeros at the end of a number are significant if the number contains a decimal point Ex 0.0200 g has 3 sig Fig Ex 3.0 has 2 sig Fig
Sig Fig Zero Rule 1
Zeros between nonzero digits are always significant Ex 1005 kg has 4 sig figs Ex 7.03 cm has 3 sig figs
combination reaction
a chemical change in which two or more substances react to form a single new substance
combustion reaction
a chemical reaction that occurs when a substance reacts with OXYGEN, releasing energy in the form of heat and light
combustion analysis
a method of obtaining empirical formulas for unknown compounds, especially those containing carbon and hydrogen, by burning a sample of the compound in pure oxygen and analyzing the products of the combustion reaction
decomposition reaction
a reaction in which a single compound breaks down to form two or more simpler substances -heating can cause this
neutralization reaction
a reaction in which an acid and a base react in an aqueous solution to produce a salt and water
Base
a substance that accept (react with)H+ ions.
strong electrolyte
a substance that completely ionizes in a solution
weak electrolyte
a substance that only partly dissociates into ions when it dissolves in water
percent yield
actual yield/theoretical yield x 100
The oxidation number of fluorine is −1 in _____________
all compounds.
What does 0 K mean?
all thermal motion ceases (absolute zero)
stoichiometric equivalence
allows the conversion of moles of reactant to moles of a product and vice versa
What is the name of Al^3+?
aluminum ion
For an atom in its elemental form, the oxidation number is...
always ZERO Ex: H and H2
net ionic equation
an equation that includes only those compounds and ions that undergo a chemical change in a reaction in an aqueous solution (form a precipitate)
complete ionic equation
an equation that shows dissolved ionic compounds as dissociated free ions
precipitate
an insoluble solid formed by a reaction in solution
displacement reaction
an ion (or atom) in a compound is replaced by an ion (or atom) of another element
spectator ion
an ion that appears on both sides of a complete ionic equation unchanged
Are non-metals cations or anions?
anions
Weak acids
any other acid that is not considered strong
Centi
c= 10^-2
Are metals cations or anions?
cations
Name the acid HClO3
chloric acid
Molecular compounds
compounds composed of different nonmetal atoms
What is the name of Cu^+ and Cu^2+?
copper (I) ion and copper (II) ion
According to Rutherford beta particles are equivalent to which subatomic particle?
electrons
What is the units used for density
g/cm^3 aka g/mL
reduction
gain of electrons Ex: H is reduced (blue)
Liquid
has a definite volume but takes the shape of its container. Is not compressible to any appreciable extent
What is standard deviation?
how much the individual measurements differ from the average
chemical equilibrium
in which the relative numbers of each type of ion or molecule in the reaction are constant over time. Chemists use half-arrows pointing in opposite directions to represent reactions that go both forward and backward to achieve equilibrium, such as the ionization of weak electrolytes
The combination of nonmetals and metal is what type of compound?
ionic compound
What is the name of Fe^2+ and Fe^3+?
iron(II) ion and iron(III) ion
An explanation for what happens...
is a theory
what happens to an aqueous ionic solid when it is put in water?
it dissociates (ion separate and disperse throughout the solution)
A substance has a solubility of .009 mol/L, is it soluble or insoluble
it is INSOLUBLE because it has a solubility of less than .01 mol/L
A substance has a solubility of .011 mol/L, is it soluble or insoluble
it is SOLUBLE because it has a solubility of greater than .01 mol/L
What is special about the acid H2SO4?
it requires two steps and only the first complete ionizes and the second only partially but it is still considered a strong electrolyte
How is matter classified?
its physical state and composition
Kilo
k=10^3
When calculating the number of atoms the number will be usually...
larger
Oxidation
loss of electrons Ex: Mg is oxidized (red)
Milli
m= 10^-3
Most matter is found as a...or...
molecule, ion (except noble gases bcuz they are stable)
Molarity equation
moles of solute/liters of solution
The oxidation number of hydrogen is usually +1 when bonded to _____________ and −1 when bonded to ______________
nonmetals, metals
How to determine the number of oxygen in an alkane
number of carbon times 2 plus 2= # of oxygen in alkane Ex: methane CH4 (1*2)+2=4
monoprotic acids yield how many H+?
one
Are molecular weight and molar mass the same thing?
pretty much
Titration
process in which a solution of known concentration is used to determine the concentration of another solution
Acid are...
proton donors (H+)
In a normal atom the number of...and... are... equal
protons and electrons
molecular equation
shows the complete formulas of all reactants and products and includes it state (s, l, g, or aq)
When calculating the number of moles the number will be usually...
small (less than 1)
What is the name of Na^+?
sodium ion
Is salt a solvent or solute?
solute
Is water a solvent or solute?
solvent
Density is dependent on...
temperature
Concentration
the amount of solute present in a given quantity of solvent or solution
The greater the amount of sig figs...
the greater the precision of the measurement
For any monatomic ion, the oxidation number equals...
the ionic charge Ex:K^+ has a +1 charge
molar mass
the mass of one mole of a substance in grams
where does most of mass of atom come from?
the nucleus (protons and neutrons)
elemental composition
the percentage composition of any element in a substance
equivalence point
the point in a titration at which the added solute reacts completely with the solute present in the solution
theoretical yield
the quantity of product that is calculated to form when all of the limiting reagent is used
limiting reactant
the substance that controls the quantity of product that can form in a chemical reaction
excess reactant
the substance that is not used up completely in a reaction
molecular weight
the sum of the atomic weights of all the atoms in a molecule -used in MOLECULAR formula
formula weight
the sum of the atomic weights of the atoms in the chemical formula of the substance -used in EMPIRICAL formula
strong bases and strong acids are similar in that....
they both completely ionize in a solution and are considered strong electrolytes
weak bases and weak acids are similar in that...
they both only partially ionize in a solution and are considered weak electrolytes
diprotic acid yield how many H+?
two
Micro
u= 10^-6
What are examples of weak electrolytes?
weak acids and weak bases
The molecular formula can be found by multiplying the empirical formula by the...
whole-number multiple
Forms of energy
work and heat
The sum of the oxidation numbers of all atoms in a neutral compound is __________. The sum of the oxidation numbers in a polyatomic ion equals _____________________
zero, the charge of the ion
What is the name of Zn^2+?
zinc ion
