Chemistry 1301 Final Exam Review

Electrons are _______ in ionic bonds.

transferred

How to calculate work

w= P x change in V -multiply Latm by 101 J to get final answer in J -when its positive, it is actually losing energy so change sign, vice versa

What does the n quantum number representl?

energy level (1s, 2s, etc)

Ionization Energy Trend

increases up and from left to right

Electron Affinity Trend

increases up and from left to right **excludes noble gases making F have the highest electron affinity

Electronegativity Trend

increases up and from left to right **excludes noble gases making F most electronegative

Convert mL to L

mL/1000 (L to mL: L x 1000)

How to calculate kinetic energy

KE=1/2mv^2 **mass is in kg **velocity is in m/s

Molarity Units

mol/L

Determine the oxidation state of Mn in KMnO4

(+1) + (x) + 4(-2)= 0 1+x-8= 0 x-7= 0 x=7 Oxidation state of Mn: +7

How to calculate moles given mass of a substance

(given mass in g) x (1 mol)/ (molar mass of substance in g)

How to calculate the mass given moles of a substance

(given moles) x (molar mass of substance in g)/ (1 mol)

Describe the difference between a molecular formula and an empirical formula. Give an example.

-A molecular formula is the exact number of each type of atom necessary to build a specific molecule. An empirical formula is simply the smallest whole number ratio between atoms in a compound. -C2H4 is the molecular formula for ethene. The empirical formula for ethene is CH2, the smallest whole number ratio between the elements.

Describe the difference between an intensive and extensive property using examples.

-An Intensive Property does NOT depend on the amount of the substance present, such as color or density. (can be used to identify a substance because it does not change with the amount of matter present) -An Extensive Property is one that does depend on the amount of the substance, such as mass or volume. (cannot be used to help identity a substance because it changes)

Describe the difference between ionic and molecular compounds. Give an example of each.

-An ionic compound is formed between a metal and a nonmetal (or polyatomic ions) and is held together through the attraction of opposite charges. An example is NaCl. -A molecular compound is usually formed between 2 or more nonmetals and is held together through the sharing of electrons between atoms. An example is CO2.

How can one compound contain both ionic and covalent bonds? Give an example.

-An ionic compound that contains a polyatomic ion -NaNO3, has both ionic bonds (that hold the sodium and nitrate ions together) as well as covalent bonds (that hold the atoms within the nitrate ion together).

Isotopes

-Isotopes are atoms with the same number of protons but that have a different number of neutrons. -Since the atomic number is equal to the number of protons and the atomic mass is the sum of protons and neutrons, we can also say that isotopes are elements with the same atomic number but different mass numbers. -number of neutrons= atomic mass-atomic number

Sig Fig Rules

-Non-zero digits are always significant. -Any zeros between two significant digits are significant. -A final zero or trailing zeros in the decimal portion ONLY are significant. Addition and Subtraction: answer must show the same number of decimal places as the number in the calculation with the least number of decimal places. Multiplication and Division: answer must show the same number of significant digits as the measurement in the calculation with the least number of significant digits.

Matter

-matter is composed of tiny particles, may be atoms or molecules. -anything that occupies space and has mass.

Atom

-the submicroscopic particle that constitutes the fundamental building block of ordinary matter. -the smallest part of an element that still has characteristics of that element.

What is the Lewis Dot Structure for Br-

.. :Br: - ..

What is the Lewis Dot Structure for Cl?

.. :Cl: .

How many grams of NaOH (MW = 40.0) are there in 250.0 mL of a 0.275 M NaOH solution?

1. 250.0 mL= .25 L 2. (0.25 L)(0.275 mol/L)= 0.06875 mol NaOH 3. 0.06875 mol NaOH x (39.997 g NaOH)/(1 mol NaOH) = 2.75 g NaOH

How many grams of H3PO4 are in 265 mL of a 1.50 M solution of H3PO4?

1. 265 mL/1000 = 0.265 L 2. (0.265 L)(1.50 mol/L)= 0.3975 mol H3PO4 3. (O.3975 mol) x (97.994 g)/(1 mol) = 39.0 g H3PO4

What is the concentration (M) of a NaCl solution prepared by dissolving 7.2 g of NaCl in sufficient water to give 425 mL of solution?

1. 425 mL= .425 L 2. (.425 L)(M)= ??mol 3. (7.2 g NaCl) x (1 mol)/(58.44 g NaCl) = 0.1232 mol NaCl 4. (.425 L)(M)=0.1232 mol NaCl 5. M= 0.29 mol/L

How to solve for volume of a gas given partial pressure

1. Calculate the pressure of gas we are trying to find the volume of by subtracting the pressure given to us from the partial pressure given Pa=(P1)-(partial pressure) 2. Convert this pressure to atm if needed, mmHg x 1atm/760 atm = atm 3. Convert the mass given (n) to moles from grams g A x (1 mol A)/(molar mass A) = mol 4. Using the mole ratio from the balanced equation (mols A to mols B, what we want), convert mol A to mol B mol A x (mol ratio B)/(mol ratioA)= mol B 5. Plug everything into V=nRT/P 6. Solve for volume (L)

How to calculate how much heat is absorbed given the enthalpy

1. Convert given mass of reactant A in g to moles g A x (mol A)/(molar mass A)= mol A 2. Multiply the value of the enthalpy in kJ by the calculated mole of A over the mol ratio of A from the balanced equation ΔH x (mol A)/(mol ratio A)= kJ

How to calculate mass of a substance given the molarity and mass of solution

1. Convert mL to L (mL/1000) if needed 2. Multiply L times molarity (L)(g/mol)= mol 3. Convert calculated moles to grams (mol) x (molar mass)/(1 mol) = g

How to calculate the concentration (M) given volume and mass

1. Convert mL to L if needed 2. Plug in values to solve for M (L)(M)=mol 3. Convert mass in g to mol (g) x (1 mol)/(molar mass) 4. put value calculated in step 3 in equation and solve for M (divide L into moles)

How to calculate the volume of a gas

1. Convert mass in g given to moles g x (1 mol A)/(molar mass A)= mol A 2. Use mole ratio from balanced equation to convert mol A to mol B mol A x (mol ratio B)/(mol ratio A)= mol B 3. Convert pressure given to atm if needed, mmHg x 1atm/760 atm = atm 4. Plug all values into V=nRT/P 5. Solve for volume in L (or mL if asked, multiply L x 1000)

How to calculate the partial pressure of a specific element/substance

1. Find the mole fraction of the element we are solving for x=na/na+nb+nc 2. Use calculated mole fraction (in moles) and multiply by total pressure given to find partial pressure of that element Pna=(mol a)(total pressure mmHg,atm)= answer (round up if needed w/ sig figs)

How to calculate the theoretical yield of a substance

1. Multiply given mass (g) of substance A by 1 mol A/molar mass of substance A (divide by molar mass) 2. Multiply this value by given mole ratio from equation, substance B/ substance A (make sure units cancel 3. Multiply this value by molar mass of substance B (molar mass/1 mol)

How to calculate mass in grams of substance A given percent yield and mass of substance B in grams

1. Plug percent yield and mass of substance B into percent yield formula (percent yield = (actual yield)/(theoretical yield) x 100% ) 2. Manipulate and solve for theoretical yield (should be g of substance B) 3. Multiply calculated value in g by (1 mol substance B)/(molar mass substance B) 4. Take calculated value (mol substance B) and multiply by mole ratio - (calculated value in mol) x (mol ratio substance A)/(mol ratio substance B) 5. Take calculated value (in mol of substance A) and multiply by (molar mass of substance A)/(1 mol substance A)

How to calculate number of moles needed to produce a number of grams of a substance in a reaction

1. Take given grams of substance A and convert to moles -(given g A) x (1 mol)/(molar mass substance A) 2. Take moles of substance A that you just calculated and use the mole ratio from the balanced equation to solve for moles of substance B needed -(calculated mol A) x (mole ratio substance b)/(mole ratio substance B)

How to calculate mass of remaining substance after a reaction given two masses of reactants

1. Take mass A (g) and multiply by 1 mol/molar mass of mass A 2. Take mass B (g) and multiply by 1 mol/molar mass of mass B 3. Subtract smaller above value (moles) from bigger (what's in excess) 4. Take calculated value (moles) and multiply by molar mass of B/1 mol = answer in grams

Oxidation State Rules

1. The oxidation number of a free element is always 0. 2. The oxidation number of a monatomic ion equals the charge of the ion. 3. The oxidation number of H is +1, but it is -1 in when combined with less electronegative elements. 4. The oxidation number of O in compounds is usually -2, but it is -1 in peroxides. 5. The oxidation number of a Group 1 element in a compound is +1. 6. The oxidation number of a Group 2 element in a compound is +2. 7. The oxidation number of a Group 17 element in a binary compound is -1. 8. The sum of the oxidation numbers of all of the atoms in a neutral compound is 0. 9. The sum of the oxidation numbers in a polyatomic ion is equal to the charge of the ion.

How to calculate the number of moles needed to react with a certain element

1. Use mole ratio from the balanced equation 2. Use given moles of substance b divided by number of moles of substance b from the equation.

How to calculate liters of an substance

1. balance equation given 2. convert g of sub A to mol (g A) x (1 mol)/(molar mass A) = mol A 3. using mole ratios convert mol A to mol B mol A x (mol ratio B)/(mol ratio A)= mol B 4. plug into V=nRT/P

How to calculate mass (g) of a substance given two molar masses

1. calculate moles of A from grams g A x (1 mol A)/(molar mass A)= mol A 2. mol A x (mole ratio B)/(mol ratio A)= mol B 3. mol B x (molar mass B)/(1 mol)= g

How to calculate mass of substance formed given two masses of reactants

1. convert mass of substance A to moles (g substance A) x (1 mol)/(molar mass of substance A) 2. convert mass of substance B to moles (g substance B) x (1 mol)/(molar mass of substance B) 3. Take these two values (in moles) and calculate number of reactions in each to find the limiting reactant. lowest value is LR (mol substance A) x (1 reaction)/(mole ratio of substance A) 4. Take value in step 1 or 2 (LR) in moles and multiply by mole ratio & convert to needed product 5. Take calculated value in step 4 (moles) and multiply by molar mass over moles (moles)(molar mass needed compound)/(1 mol)

How to calculate mass of a substance (product) given two volumes and two molarities (reactants)

1. multiply mL to L 2. multiply (L substance A)(M substance A)= mol A 3. multiply (L substance B)(M substance B)= mol B 4. find limiting reactant, if 1:1 mole ratio, use values just calculated. If not 1:1, calculate number of reactions per substance - mol A x (1 reactions)/ mol ratio of A - mol B x (1 reactions)/ mol ratio of B lowest value is LR 5. take LR (moles) and convert to desired units of a certain substance (product) using mole ratio -mol A/B x (mol ratio desired)/(mol ratio A/B) 6. take calculated value in new units of desired substance and convert to grams -mol desired x (molar mass desired)/(1 mol desired)= g

How to calculate the molar mass of a gas

1. n=PV/RT 2. plug in all values for formula 3. n=(atm)(L)/(0.08206 Latm/molK)(K) = mol 4. given grams/ calculated mol = answer g/mol

How to calculate volume of a substance given molarity, mass, and percent yield

1. plug in given values to percent yield equation % yield= (actual yield g)/theoretical yield x 100%, solve for theoretical 2. use theoretical mass and convert to moles g x (1 mol)/(molar mass) = mol 3. look at mole ratio from what you are given to what you want, multiply mols calculated in step 2 by mol ratio if over 1:1 4. plug all in to calculate for mL/L (mL)(M)= mol 5. solve for mL/L, convert to either mL or L if needed

How to calculate mass of thermal decomposition

1. plug in values for n=PV/RT and solve for n in moles 2. use mole ratio (from what was produced in the reaction to what we are trying to find) to convert mol A to mol B mol A x (mol ratio B)/(mol ratio A)= mol B 3. Convert mol B to grams mol B x (molar mass B)/(1 mol)

How to calculate the total pressure

1. use P= nRT/V 2. plug in all given values for n= moles, R= gas constant (0.08206 Latm/molK), T= temp in K, V= L given 3. solve for pressure, in atm or another unit of pressure

How to calculate density of a gas

1. use PV=nRT 2. isolate the variable that we are solving for, volume, V=nRT/P 3. plug in all given values V=(mol)(0.08206 Latm/molK)(K)/atm = L 4. Divide grams (molar mass of one mol of gas given in problem) by L calculated g/L = answer

Give the complete electronic configuration for Br-.

1s22s22p63s23p64s23d104p6

How many core electrons are in Mg2+

2

How many different values of ml are possible in the 2p sublevel?

3

A flash drive contains 4 gigabytes. How many bytes does it contain?

4,000,000,000 bytes

How many different values of ml are possible in the 3d sublevel?

5

Calculate the mass percent composition of oxygen in Al2(SO4)3

56.14% -------------------------------- molar mass of Al2(SO4)3= 342g/mol oxygen: 3 x 4x 16g = 192g 192g/342g x 100 = 56.14%

How many different values of ml are possible in the 4f sublevel?

7

Precipitation Reaction

A precipitation reaction refers to the formation of an insoluble salt when two solutions containing soluble salts are combined. The insoluble salt that falls out of solution is known as the precipitate, hence the reaction's name. NaCl (aq) + AgNO3 (aq) = AgCl (s) + NaNO3 (aq)

An ion has 8 protons, 9 neutrons, and 10 electrons, The symbol for the ion is _____

A) 17O^2-

The atomic number of an atom of 80^Br is

A) 35

What is the identity of element Q if the ion Q2+ contains 10 electrons?

A) Mg ------------------------- If Q2+ ion has 10 electrons then element Q should have 10+ 2 electrons. (no of electrons in the ion + no of electrons lost)

The number 6.022x10^23 is called

Avogadro's number

A mass of mercury occupies 0.950 L. What volume would an equal mass of ethanol occupy? the density of mercury is 13.546 g/mL and the density of ethanol is 0.789 g/mL.

B) 16.3 L (.950 L) x (1000mL / 1L) x (13.546g / 1mL) x (1mL / .789g) = 16,310 mL = 16.3 L

How many significant figures are there in the answer to the following problem? (9.992 x 3.200) + 0.610 = 32.584

C) 3 sig figs

Which of the following is the lowest temperature? A) 42 degrees c B) 318 K C) 57 degrees F D) All of these temperatures are equal.

C) 57 degrees F ---------------------------- A) 42 c B) 318K-273K= 45 degrees c C) (57 degrees F - 32)* 5/9= 13.89 degrees c

What type of bonding is found in the compound O F2

C) Covalent bonding ------------------------------- covalent bond: a chemical bond between atoms that occurs when they share one or more electrons. Since neither atom is strong enough to attract an electron from the other, they share electrons in a covalent bond. These bonds form a fixed, definite shape. They generally occur between two non-metallic atoms. ionic bond: a chemical bond between atoms that occurs when they are attracted because of opposite charges. An ionic bond can form between a cation and anion because one has a positive charge and the other has a negative charge. These bonds do not have a definite shape. They generally occur between a metallic and a non-metallic atom.

In which set do all elements tend to form anions in binary ionic compounds? a) Li, Na, K b) C, S, Pb c) N, O, I d) K, Fe, Br

C) N,O,I ----------------------------- this is because they are non-metals and electronegative, so they gain electrons easily and form anions.

Given the equation C2H6 (g) + O2 (g) → CO2 (g) + H2O (g) (not balanced) Determine the number of liters of CO2 formed at STP when 240.0 grams of C2H6 is burned in excess oxygen gas.

C2H6 (g) + 7O2(g) = 2CO2 (g) + 3H2O (g) 1. 240.0 g C2H6 x (1 mol)/(30.07 g)= 7.9814 mol C2H6 2. 7.9814 mol C2H6 x (2 mol CO2)/(1 mol C2H6)= 15.963 mol CO2 3. V=(15.963 mol)(0.08206 Latm/molK)(273K)/(1 atm)= 357.605~ 358 L

Balance the following equation C9H20 + O2 = H2O + CO2

C9H20 + 1402 = 10H2O + 9CO2

What is the Lewis Dot Structure for Ca2+

Ca2+

Use Lewis theory to determine the chemical formula for the compound formed between Ca and N.

Ca3N2 -find the charges of both Ca2+, N3- -swap charges and drop as subscripts

An atom of 131^ Xe contains ____ electrons.

D) 54 electrons (mass number)

Identify the chemical symbol of element Q in 80^Q 34

D) Se (Selenium)

SI prefixes

Deka: da, 10^1 Hecto: h, 10^2 Kilo: k, 10^3 Mega: M, 10^6 Giga: G, 10^9 Tera: T, 10^12 Peta: P, 10^15 Exa: E, 10^18 Seta: Z, 10^21 Yotta: Y, 10^24 Deci: d, 10^-1 Centi: c, 10^-2 Milli: m, 10^-3 Micro: u, 10^-6 Nano: n, 10^-9 Pico: p, 10^-12 Femto: f, 10^-15 Atto: a, 10^-18 Zepto: z, 10^-21 Yocto: y, 10^-24

The Law of Conservation of Energy

Energy cannot be created or destroyed.

Give an example of a halogen.

F, Cl, Br, I (group 17)

Which noble gas has the highest ionization energy?

Helium (He)

Define Ionization Energy

Ionization energy is the energy required to remove an electron from an ion or an atom.

Describe the difference between ions and isotopes.

Ions have the loss or gain of electrons (have a net electric charge), Isotopes differ in the number of neutrons

Below is a list of successive ionization energies (in kJ/mol) for a period 3 element. Identify the element and explain how you came to that conclusion. IE2= 2250 IE3= 3360 IE4=4560 IE5=7010 IE6=8500 IE7=27,1000

It is sulfur (S). This is because the large increase in ionization energy between IE6 and IE7 shows that there are 6 valence electrons in this element. The only period 3 element that contains 6 valence electrons is sulfur (S).

What is the Lewis Dot Structure for Mg

Mg:

List the spectator ions in the following reaction. Ba+2(aq) + 2OH-(aq) + 2 Na+(aq) + CO3-2(aq) → 2 Na+(aq) + 2OH-(aq) + BaCO3 (s)

Na+, OH-

A sample of liquid isopropyl alcohol is placed in a sealed container. Some of the volatile isopropyl alcohol vaporizes. Does the mass of the sealed container and its contents change during the vaporization? Explain.

No, the mass stays the same during the vaporization. This is because the isopropyl alcohol is just in a different physical state now. Because The Law of Conservation of Mass states matter cannot be created or destroyed, the mass in the container will stay constant.

Define Paramagnetic

Paramagnetic is when an UNPAIRED electron is attracted by an external magnetic field. -If an element has an odd number of electrons, then it is paramagnetic.

What is the difference between a physical property and a chemical property?

Physical Property: something that can be observed without changing the chemical identity of the substance, such as color or scent. Chemical Property: can only be observed while the chemical identity of the substance is changing, such as sodium metal's tendency to react with water to form hydrogen gas and sodium hydroxide.

The atomic number is equal to the number of

Protons

Why do elements in the same group tend to have similar chemical properties?

Since elements in the same group have the same number of valence electrons (similar electron configurations) they tend to have similar chemical reactivity, since chemical reactions typically involve valence electrons.

Energy

The ability to do work or produce heat. Kinetic: energy of motion Potential: energy of position

Why doesn't a mass spectrum of silver have a peak at 107.9 amu?

The average atomic mass of silver is 107.9 amu, but there are no atoms of silver that weigh 107.9 amu. One isotope weighs more and another weighs less.

Core Electrons

The electrons in the inner-most shells of an atom; electrons in completed shells. These electrons are not involved in forming bonds.

Valence Electrons

The electrons in the outermost shell (main energy level) of an atom; these are the electrons involved in forming bonds.

Acid-Base Reaction

When an acid and base mix together, neutralize one another's properties, and form a salt and water. H2SO4 (aq) + 2LiOH (aq) = 2H20 (l) + Li2SO4 (aq)

Give the ground state electron configuration for Cd+2

[Kr]5s24d8

Gas Evolution Reaction

a reaction in which two aqueous solutions are mixed and a gas forms, resulting in bubbling A gas evolution reaction is a chemical reaction in which one of the end products is a gas such as oxygen or carbon dioxide. HCl (aq) + (NH4)2S (aq) = H2S (g) + 2NH4Cl (aq)

How many moles are there in 3.00 g of ethanol, CH3CH2OH? a) 0.0652 mol b) 0.00725 mol c) 15.3 mol d) 138 mol

a) 0.0652 mol -------------------------------- 3.00 g x 1 mol/46.07 g (molar mass)= 0.06512

How many moles of BCl3 are needed to produce 10.0 g of HCl(aq) in the following reaction? BCl3(g) + 3 H2O(l) → 3 HCl(aq) + B(OH)3(aq) a) 0.0914 mol b) 0.823 mol c) 0.274 mol d) 10.9 mol

a) 0.0914 mol ------------------------------------------ (10.0g HCl) x (1 mol HCl)/(36.46 g HCl) = 0.274 mol HCl (0.274 mol HCl) x (1 mol BCl3)/(3 mol HCl) = 0.0913 mol BCl3

A student prepared a stock solution by dissolving 10.0 g of KOH in enough water to make 150. mL of solution. She then took 15.0 mL of the stock solution and diluted it with enough water to make water to make 65.0 mL of a final solution. What is the concentration of KOH for the final solution? a) 0.274 M b) 3.65 M c) 0.356 M d) 2.81 M

a) 0.274 M ------------------------------------- (0.065 L)(M)=0.1782 mol KOH M=2.74 mol/L

In the laboratory, hydrogen gas is usually made by the following reaction: Zn(s) + 2 HCl(aq) → H2(g) + ZnCl2(aq) How many liters of H2 gas, collected over water at an atmospheric pressure of 752 mm Hg and a temperature of 21.0°C, can be made from 3.566 g of Zn and excess HCl? The partial pressure of water vapor is 18.65 mm Hg at 21.0°C. a) 1.36 L b) 0.0975 L c) 1.33 L d) 1.30 L

a) 1.36 L ------------------------------ 1. PH2= 752 mmHg- 18.65 mmHg= 733.4 mmHg 2. (733.4 mmHg) x (1 atm)/(760 atm)= 0.964 atm 3. (3.566g Zn) x (1 mol Zn)/(65.38 g Zn)= 0.0545 mol Zn 4. Using mol ratio from balanced equation (1:1 from Zn to H2), (0.0545 mol Zn) x (1 mol H2)/(1 mol Zn)= 0.0545 mol H2 5. Plug all into V=nRT/P V=(0.0545 mol)(0.08206 Latm/molK)(294K)/(0.964 atm)= 1.364 L

How many milliliters of 0.200 M FeCl3 are needed to react with an excess of Na2S to produce 1.38 g of Fe2S3 if the percent yield for the reaction is 65.0%? 3 Na2S(aq) + 2 FeCl3(aq) → Fe2S3(s) + 6 NaCl(aq) a) 102 mL b) 25.5 mL c) 51.1 mL d) 43.1 mL

a) 102 mL ---------------------------------- 1. 65.0%= 1.38g/theoretical x 100 = 2.12g 2. 2.12 g Fe2S3 x 1 mol/ 207.9 g = 0.0102 mol Fe2S3 3.using mol ratio between FeCl3 and Fe2S3, 0.0102 x 2 = 0.0204 mol 4. (mL)(0.200 mol/L)=0.0204 mol= 0.102 L 5. 0.102 L x 1000= 102 mL

Using the following equation for the combustion of octane, calculate the amount of grams of carbon dioxide formed from 100.0 g of octane. The molar mass of octane is 114.33 g/mole. The molar mass of carbon dioxide is 44.0095 g/mole. 2 C8H18 + 25 O2 → 16 CO2 + 18 H2O ΔH°rxn = -11018 kJ a) 307.9 g b) 792.3 g c) 260.1 g d) 800.1 g

a) 307.9 g ---------------------------------- 1. 100g C8H18 x (1 mol)/(114.33 g)= 0.87466 mol C8H18 2. 0.87466 mol C8H18 x (16 mol CO2)/(2 mol C8H18)= 6.997 mol CO2 3. 6.997 mol CO2 x (44.0095 g CO2)/(1 mol CO2)= 307.9 g CO2

A 0. 286-g sample of gas occupies 125 mL at 60.cm of Hg and 25°C. What is the molar mass of the gas? a) 71 g/mol b) 59 g/mol c) 5.9 g/mol d) 44 g/mol

a) 71 g/mol ---------------------------------- 1. n=PV/RT 2. 60cmHg = 600mmHg = 600/760 = 0.789 atm 3. 125 mL/1000= 0.125 L 4. 25+273= 298K 5. n=(0.789 atm)(0.125 L)/ (0.08206 Latm/molK)(298K) = 0.00403 mol 6. 0.286 g/0.00403 mol = 71 g/mol

How many mL of O2 gas at 25°C and 755 mm Hg pressure can be produced from the thermal decomposition of 0. 300 grams of KClO3(s) according to the chemical equation shown below? 2 KClO3(s) → 2 KCl(s) + 3 O2(g) a) 90.4 mL b) 40.2 mL c) 181 mL d) 30.1 mL

a) 90.4 mL --------------------------- 1. 0.300 g KClO3 x (1 mol KClO3)/(122.55 g) = 0.00245 mol KClO3 2. 0.00245 mol KClO3 x (3 mol O2)/(2 mol KClO3)= 0.003675 mol O2 3. 755 mmHg x (1 atm)/(760 mmHg)= 0.9934 atm 4. V= (0.003675 mol)(0.08206 Latm/molK)(298K)/(0.9934 atm)= 0.09047 L 5. 0.09047 L x 1000= 90.47 mL

Which has the lowest electronegativity? a) Ba b) Sr c) I d) At

a) Ba

Which element has the highest first electron affinity? a) O b) Mg c) Na d) Ne

a) O electron affinity trend increases from left to right, going up. Excludes noble gases (noble gases are very small)

Which one of the following compounds contains ionic bonds? a) SrO b) SiO2 c) PBr3 d)HBr

a) SrO (metal and non-metal)

Of the following, which element has the highest first ionization energy? a) carbon b) boron c) beryllium d) lithium

a) carbon ionization energy increases on the periodic table from left to right, going up. Carbon is the right-most, highest up element to the right corner.

Rb2S is named a) rubidium sulfide b) rubidium sulfur c) rubidium disulfide d) rubidium (II) sulfide

a) rubidium sulfide

Combustion Reaction

an exothermic reaction in which something reacts with oxygen. The combustion of organic compounds usually takes the form organic compound + oxygen => water + carbon dioxide. CH4 (g) + 2O2 (g) = CO2 (g) + 2H2O (g)

Oxidation-Reduction Reaction

any chemical change in which one species is oxidized (loses electrons) and another species is reduced (gains electrons); also called redox reaction. Mg (s) + Cu(NO3)2 (aq) = Mg(NO3)2 (aq) + Cu (s)

How much heat is absorbed when 45.00 g of C(s) reacts in the presence of excess SO2(g) to produce CS2(l) and CO(g) according to the following chemical equation? 5C(s)+2SO2(g)→CS2(l)+4CO(g) ΔH°=239.9kJ a) 898.5 kJ b) 179.8 kJ c) 2158 kJ d) 239.9 kJ

b) 179.8 kJ ------------------------------- 1. 45.oog C x (1 mol C)/(12 g C)= 3.75 mol C 2. 239.9 kJ x (3.75 mol C)/(5 mol C)= 179.925 kJ

What is the mass of 0.500 mol of dichlorodifluoromethane, CCl2F2? a) 121 g b) 60.5 g c) 242 g d) 4.14x10^-3 g

b) 60.5 g --------------------------------- 0.500 mol x 120.91 g (molar mass)/1 mol = 60.455g

Which has the highest electronegativity? a) Ti b) Cl c) Se d) S

b) Cl

What is the chemical formula for iron (III) sulfate? a) Fe3S b) Fe2(SO4)3 c)Fe2S3 d)Fe3SO4

b) Fe2(SO4)3

An aqueous solution of H2S is named a) sulfurous acid b)hydrosulfuric acid c) sulfuric acid d) hydrosulfurous acid

b) hydrosulfuric acid

For a particular process that is carried out at constant pressure, q = 145 kJ and w = -35 kJ. Therefore, a) ΔE=180kJandΔH=145kJ. b) ΔE=110kJandΔH=145kJ. c) ΔE=145kJandΔH=180kJ. d) ΔE=145kJandΔH=110kJ.

b) ΔE=110kJ and ΔH=145kJ. ------------------------------------- ΔE=q+w ΔE= 145+(-35)=110kJ

The chemical formula for nitrous acid is a)H3N (aq) b) HNO2 (aq) c)H2N2O6 (aq) d) HNO3 (aq)

b)HNO2 (aq)

Lithium and nitrogen react to produce lithium nitride: 6Li(s) + N2(g) = 2Li3N(s) How many moles of N2 are needed to react with 0.500 mol of Lithium? a) 0.500 b) 3.00 c) 0.0833 d) 1.50 e) 0.167

c) 0.0833 -------------------------------- 0.500 mol Li/6 mol Li = 0.083 mol you need 6 Li's per every 1 N2 you are using. Thus, you divide your moles of N2 by six to find how many moles of Li you'll need.

If the percent yield for the following reaction is 65.0%, how many grams of KClO3 are needed to produce 32.0 g of O2? 2 KClO3(s) → 2 KCl(s) + 3 O2(g) a) 81.7 g b) 283 g c) 126 g d) 53.1 g

c) 126 g ------------------------------- 1. 65.0%= 32.0g/theoretical yield x 100 2. manipulate and get theoretical yield = 32.0gx100%/65.0% = 49.23gO2 3. (49.23g O2) x (1 mol O2)/(32.0 g O2)= 1.54 molO2 4. (1.54 mol O2) x (2 mol KClO3)/(3 mol O2)=1.026 mol KClO3 5. (1.026 mol KClO3) x (122.55 g KClO3)/(1 mol KClO3)= 125.7 ~ 126 g KClO3

The specific heat capacity of liquid mercury is 0.14 J/gK. How many joules of heat are needed to raise the temperature of 5.00 g of mercury from 15.0°C to 36.5°C? a) 7.7 x 10^2 J b) 0.0013 J c) 15 J d) 36 J e) 1.7 J

c) 15 J -------------------------------- q=(m)(Cs)(change in T) q=(5.00g)(0.14 J/gK)(36.5 C-15.O C) q=(5.00g)(0.14 J/gK)(21.5 C)= 15.05 J

Magnesium burns in air with a dazzling brilliance to produce magnesium oxide: 2Mg(s)+O2(g) → 2MgO(s) When 4.00 g of magnesium burns, the theoretical yield of magnesium oxide is __________ g. a) 4.00 b) 0.165 c) 6.63 d) 13.3 e) 3.32

c) 6.63 ----------------------------- (4.00g Mg) x (1 mol Mg)/(24.305 g Mg) x (2 mol MgO)/(2 mol Mg) x (40.305g MgO)/(1 mol MgO) = 6.63g MgO

Which ionization process requires the most energy? a) F(g) → F+(g) + e- b) O+(g) → O2+(g) + e- c) F+(g) → F2+(g) + e- d) O(g) → O+(g) + e-

c) F+(g) → F2+(g) + e- -F has higher ionization energy than O, so either a or c. -more atoms were ionized in part c, so c must be the answer with more energy being used.

The chemical formula for lithium peroxide is a)Li2O b)LiO2 c)Li2O2 d)LiOH

c) Li2O2

Identify the compound with metallic bonding a) S b) NaCl c) Li d) He e) H2O

c) Lithium Lithium is a metal, so pure lithium metal would just have lithium atoms bonded together. The way they bond together is called metallic bonding, where lithium atoms release electrons into a "sea" and become cations, and bond with these spare electrons in the "sea", called delocalized electrons.

When silver nitrate reacts with barium chloride, silver chloride and barium nitrate are formed. How many grams of silver chloride are formed when 10.0 g of silver nitrate reacts with 15.0 g of barium chloride? a) 9.40 g b) 18.8 g c) 8.44 g d) 11.9 g

c)8.44 g -------------------------------------- 1. 2AgNO3 + BaCl2 = 2AgCl + Ba(NO3)2 2. AgNO3: 10.0g AgNO3 x (1 mol)/(169.87g)= 0.059 3. BaCl2: 15.0g BaCl2 x (1 mol)/(208.23g)= 0.072 4. 0.059 mol AgNO3 x 1 reaction/2 mol = 0.0295 <--LR 0.072 mol BaCl2 x 1 reaction/1 mol = 0.072 5. 0.059mol AgNO3 x (2 mol AgCl)/(2 mol AgNO3)= 0.059 mol AgCl 6. 0.059 mol AgCl x (143.32 g)/(1 mol)= 8.44g

Calculate the work, w, gained or lost by the system when a gas expands from 15 L to 40 L against a constant external pressure of 1.5 atm. **101.3 L ∙ atm = 101 J a) +6.1 kJ b) +3.8 kJ c) -6.1 kJ d) -3.8 kJ

d) -3.8 kJ -------------------------- w= P x change in V 1. w= (1.5 atm)(40L-15L) 2. w= (1.5 atm)(25L) 3. w= 37.5 Latm x 101 J= 3787.5 J 4. 3787.5 J/1000= 3.7875 kJ ~ 3.8kJ, losing when it is positive

How many grams of KCl(s) are produced from the thermal decomposition of KClO3(s) which produces 50.0 mL of O2(g) at 25°C and 1.00 atm pressure according to the chemical equation shown below? 2 KClO3(s) → 2 KCl(s) + 3 O2(g)? a) 0.167 g b) 0.304 g c) 0.152 g d) 0.102 g

d) 0.102 g --------------------------- 1. n= (1.00 atm)(0.05 L)/(0.08206 Latm/molK)(298K)= 0.00204 mol KClO3 2. 0.00204 mol O2 x (2 mol KCl)/(3 mol O2)= 0.00136 mol KCl 3. 0.00135 mol x 74.5513g/1mol= 0.102 g

When 31.2 mL of 0.500 M AgNO3 is added to 25.0 mL of 0.300 M NH4Cl, how many grams of AgCl are formed? AgNO3(aq) + NH4Cl(aq) → AgCl(s) + NH4NO3(aq) a) 3.31 g b) 6.44 g c) 2.24 g d) 1.07 g

d) 1.07 g -------------------------------------------- 1. (0.0312 L)(0.500 mol/L)= 0.0156 mol AgNO3 2. (0.025 L)(0.300 mol/L)= 0.0075 mol NH4Cl 3. is a 1:1 mole ratio, but -0.0075 mol NH4Cl x (1 reactions)/(1 mol) = 0.0075 rxn <--- LR -0.0156 mol AgNO3 x (1 reactions)/(1 mol) = 0.0156 rxn 4. 0.0075 mol NH4Cl x 1 mol AgCl/1 mol NH4Cl = 0.0075 mol AgCl 5. 0.0075 mol AgCl x (143.32 g)/(1 mol AgCl) = 1.07g AgCl

Calculate the kinetic energy of a 150 g baseball moving at a speed of 39. m/s ( 87 mph). a) 5.8 × 10^3 J b) 1.1 × 10^5 J c) 5.8 J d) 1.1 × 10^2 J

d) 1.1 x 10^2 J ------------------------------ KE= 1/2mv^2 KE= (0.5)(0.15kg)(1521 m/s) KE= (.075 kg)(1521 m/s)= 114.075 ---> 1.1 x 10^2 J

What is the total pressure in a 6.00-L flask which contains 0.127 mol of H2(g) and 0.288 mol of N2(g) at 20.0°C? a) 0.681 atm b) 0.510 atm c) 1.16 atm d) 1.66 atm

d) 1.66 atm --------------------------------------- 1. P= nRT/V 2. P= (0.415 mol)(0.08206 Latm/molK)(293K)/(6.00L)= 1.663 atm

A balloon contains 0.76 mol N2, 0.18 mol O2, 0.031 mol He and 0.026 mol H2 at 749 mm Hg. What is the partial pressure of O2? a) 23 mmHg b) 20 mmHg c) 570 mmHg d) 140 mmHg

d) 140 mmHg ----------------------------- 1. x= (0.18 mol)/(0.76 mol)+(0.18 mol)+(0.031 mol)+(0.026 mol)= 0.1805 mol 2. Po2= (0.1805 mol)(749 mmHg)= 135.19 mmHg ~ 140 mmHg

Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide: CaO (s) + H2O (l) → Ca(OH)2 (s) A 4.50-g sample of CaO is reacted with 4.34 g of H2O. How many grams of water remain after the reaction is complete? a) 0.00892 b) 0.161 c) 0.00 d) 2.90 e) 1.04

d) 2.90 ------------------------------------- moles CaO = 4.50 g/ 56.077 g/mol= 0.0802 moles H2O = 4.34 g/18.02 g/mol= 0.241 moles H2O in excess, 0.241 - 0.0802 =0.161 mass H2O in excess = 0.161 x 18.02 =2.89 g ~ 2.90g H20

Identify the compound with ionic bonding a) Li b) He c) H2O d) NaCl e) S

d) NaCl It is an ionic bond created by an attraction between the +1 sodium cation and the -1 chlorine anion.

The compound Cu(IO3)2 is named a) copper(I) iodate(II) b) copper(I) iodate c) copper iodate(II) d) copper(II) iodate

d) copper(II) iodate

Use the standard reaction enthalpies given below to determine ΔH°rxn for the following reaction: Given: 4SO3(g) →4S(s)+6O2(g). ΔH°rxn= ? SO2(g) → S(s) + O2(g). ΔH°rxn = +296.8 kJ 2 SO2(g) + O2(g) → 2 SO3(g) ΔH°rxn = -197.8 kJ a) -494.6 kJ b) -692.4 kJ c) -293.0 kJ d)-791.4 kJ e) 1583 kJ

e) 1583 kJ ------------------------------------- SO2(g)→S(s)+O2(g). ΔH°rxn = +296.8kJ(X4)=1187.2 kJ 2SO2(g)+O2(g)→2SO3(g) ΔH°rxn = -197.8 kJ(X2)=395.6 kJ (1187.2 kJ)+(395.6 kJ)= 1583 kJ

The density of krypton gas at 1.21 atm and 50.0°C is __________ g/L. a) 0.0456 b) 0.262 c) 0.296 d) 7.65 e) 3.82

e) 3.82 ----------------------------------- PV=nRT V=nRT/P V=(1 mol)(0.08206 Latm/molK)(323K)/1.21 atm = 21.91 L g/L, so (83.8 g)/(21.91 L)= 3.82

Identify the compound with covalent bonding a) Li b) S c) He d) NaCl e) H2O

e) H2O Water is covalent because the electronegativity difference between H and O is small enough that most of the time, the electrons are shared.

What does the l quantum number represent?

orbital type (s,p,d,f)

How to calculate percent yield

percent yield = (actual yield)/(theoretical yield) x 100%

How to calculate joules using specific heat

q=(m)(Cs)(change in T) m= mass in g Cs= specific heat of substance (constant) change in T= final temp- initial temp degrees Celsius solve for q

What does the ml quantum number represent?

specific orbital (# of orbitals: from -2 to 2 for example)

What does the ms quantum number represent?

spin (down arrow, up arrow, -1/2, +1/2)