Introductory Chemistry: Concepts and Critical Thinking

Charles H. Corwin

Chapter 9

The Mole Concept - all with Video Answers

Educators

Chapter Questions

Problem 1

Refer to the periodic table and state the atomic mass (in amu) of one atom for each of the following metals:
(a) lithium
(b) titanium
(c) gold
(d) bismuth

Nicole Smina

Nicole Smina

Numerade Educator

Problem 2

Refer to the periodic table and state the atomic mass (in amu) of one atom for each of the following nonmetals:
(a) carbon
(b) sulfur
(c) selenium
(d) iodine

Nicole Smina

Numerade Educator

Problem 3

Refer to the periodic table and state the mass of $6.02 \times 10^{23}$ atoms of each of the following metals:
(a) lithium
(b) titanium
(c) gold
(d) bismuth

Nicole Smina

Numerade Educator

Problem 4

Refer to the periodic table and state the mass of $6.02 \times 10^{23}$ atoms of each of the following nonmetals:
(a) carbon
(b) sulfur
(c) selenium
(d) iodine

Nicole Smina

Numerade Educator

Problem 5

State the number of particles in each of the following:
(a) $1 \mathrm{~mol}$ of carbon atoms, $\mathrm{C}$
(b) 1 mol of methane molecules, $C H_{4}$

Nicole Smina

Numerade Educator

Problem 6

State the number of particles in each of the following:
(a) $1 \mathrm{~mol}$ of silicon atoms, $\mathrm{Si}$
(b) 1 mol of silane molecules, $\mathrm{SiH}_{4}$

Nicole Smina

Numerade Educator

Problem 7

State the number of moles represented by each of the following:
(a) $6.02 \times 10^{23}$ atoms of lithium, $\mathrm{Li}$
(b) $6.02 \times 10^{23}$ molecules of bromine, $\mathrm{Br}_{2}$

Nicole Smina

Numerade Educator

Problem 8

State the number of moles represented by each of the following:
(a) $6.02 \times 10^{23}$ atoms of sulfur, S
(b) $6.02 \times 10^{23}$ molecules of sulfur dioxide, $\mathrm{SO}_{2}$

Nicole Smina

Numerade Educator

Problem 9

Calculate the number of particles in each of the following:
(a) 0.100 mol zinc atoms, $Z n$
(b) 0.200 mol chlorine molecules, $C l_{2}$
(c) 0.300 mol zinc chloride formula units, $Z \mathrm{nCl}_{2}$

Nicole Smina

Numerade Educator

Problem 10

Calculate the number of particles in each of the following:
(a) 0.250 mol calcium atoms, Ca
(b) 0.500 mol fluorine molecules, $\mathrm{F}_{2}$
(c) 0.750 mol calcium fluoride formula units, $\mathrm{CaF}_{2}$

Nicole Smina

Numerade Educator

Problem 11

Calculate the number of moles containing each of the following:
(a) $1.00 \times 10^{22}$ atoms of manganese, $\mathrm{Mn}$
(b) $2.00 \times 10^{23}$ molecules of sulfur trioxide, $S O_{3}$
(c) $3.00 \times 10^{24}$ formula units of manganese(II) sulfate, $\mathrm{MnSO}_{4}$

David Collins

Numerade Educator

Problem 12

Calculate the number of moles containing each of the following:
(a) $2.50 \times 10^{22}$ atoms of iron, Fe
(b) $5.00 \times 10^{23}$ molecules of carbon dioxide, $\mathrm{CO}_{2}$
(c) $7.50 \times 10^{24}$ formula units of iron(II) carbonate, $\mathrm{FeCO}_{3}$

David Collins

Numerade Educator

Problem 13

State the molar mass for each of the following:
(a) aluminum, Al
(b) silicon, Si
(c) oxygen, $\mathrm{O}_{2}$
(d) sulfur, $S_{8}$

Nicole Smina

Numerade Educator

Problem 14

State the molar mass for each of the following:
(a) arsenic, As
(b) germanium, Ge
(c) ozone, $\mathrm{O}_{3}$
(d) phosphorus, $P_{4}$

Nicole Smina

Numerade Educator

Problem 15

Calculate the molar mass for each of the following:
(a) calcium sulfide, $\mathrm{CaS}$
(b) calcium sulfate, $\mathrm{CaSO}_{4}$
(c) iron(II) acetate, $\mathrm{Fe}\left(\mathrm{C}_{2} \mathrm{H}_{3} \mathrm{O}_{2}\right)_{2}$
(d) iron(II) phosphate, $\mathrm{Fe}_{3}\left(\mathrm{PO}_{4}\right)_{2}$

David Collins

Numerade Educator

Problem 16

Calculate the molar mass for each of the following:
(a) bromine iodide, BrI
(b) tribromine octaoxide, $\mathrm{Br}_{3} \mathrm{O}_{8}$
(c) glycerin, $\mathrm{C}_{3} \mathrm{H}_{5}(\mathrm{OH})_{3}$
(d) nitroglycerin, $\mathrm{C}_{3} \mathrm{H}_{5} \mathrm{O}_{3}\left(\mathrm{NO}_{2}\right)_{3}$

David Collins

Numerade Educator

Problem 17

Calculate the mass in grams for each of the following:
(a) $2.95 \times 10^{23}$ atoms of mercury, $\mathrm{Hg}$
(b) $1.16 \times 10^{22}$ molecules of nitrogen, $\mathrm{N}_{2}$
(c) $5.05 \times 10^{21}$ formula units of barium chloride, $\mathrm{BaCl}$ ?

David Collins

Numerade Educator

Problem 18

Calculate the mass in grams for each of the following:
(a) $1.21 \times 10^{24}$ atoms krypton, $\mathrm{Kr}$
(b) $6.33 \times 10^{22}$ molecules of dinitrogen oxide, $\mathrm{N}_{2} \mathrm{O}$
(c) $4.17 \times 10^{21}$ formula units of magnesium perchlorate, $\mathrm{Mg}\left(\mathrm{ClO}_{4}\right)_{2}$

David Collins

Numerade Educator

Problem 19

Calculate the number of particles in each of the following:
(a) 1.50 g potassium, $K$
(b) $0.470 \mathrm{~g}$ oxygen, $\mathrm{O}_{2}$
(c) $0.555 \mathrm{~g}$ silver chlorate, $\mathrm{AgClO}_{3}$

David Collins

Numerade Educator

Problem 20

Calculate the number of particles in each of the following:
(a) 7.57 g platinum, $P t$
(b) $3.88 \mathrm{~g}$ ethane, $\mathrm{C}_{2} \mathrm{H}_{6}$
(c) 0.152 g aluminum chloride, $\mathrm{AlCl}_{3}$

Ronald Prasad

Numerade Educator

Problem 21

Calculate the mass in grams for a single atom of the following elements:
(a) beryllium, Be
(b) sodium, $\mathrm{Na}$
(c) cobalt, Co
(d) arsenic, As

David Collins

Numerade Educator

Problem 22

Calculate the mass in grams for a single molecule of the following compounds:
(a) methane, $\mathrm{CH}_{4}$
(b) ammonia, $\mathrm{NH}_{3}$
(c) sulfur trioxide, $\mathrm{SO}_{3}$
(d) nitrogen dioxide, $\mathrm{NO}_{2}$

David Collins

Numerade Educator

Problem 23

State standard conditions for a gas in degrees Celsius and atmospheres.

Nicole Smina

Numerade Educator

Problem 24

State standard conditions for a gas in Kelvin units and atmospheres.

Nicole Smina

Numerade Educator

Problem 25

Calculate the density for each of the following gases at STP:
(a) argon, $\mathrm{Ar}$
(b) chlorine, $\mathrm{Cl}_{2}$
(c) methane, $\mathrm{CH}_{4}$
(d) ethane, $\mathrm{C}_{2} \mathrm{H}_{6}$

Nicole Smina

Numerade Educator

Problem 26

Calculate the density for each of the following gases at STP:
(a) xenon, $\mathrm{Xe}$
(b) fluorine, $\mathrm{F}_{2}$
(c) propane, $\mathrm{C}_{3} \mathrm{H}_{8}$
(d) butane, $C_{4} H_{10}$

David Collins

Numerade Educator

Problem 27

Calculate the molar mass for each of the following gases given the STP density:
(a) oxygen, $1.43 \mathrm{~g} / \mathrm{L}$
(b) phosphine, $1.52 \mathrm{~g} / \mathrm{L}$
(c) nitrous oxide, $1.97 \mathrm{~g} / \mathrm{L}$
(d) Freon-12, $5.40 \mathrm{~g} / \mathrm{L}$

Nicole Smina

Numerade Educator

Problem 28

Calculate the molar mass for each of the following gases given the STP density:
(a) ozone, $2.14 \mathrm{~g} / \mathrm{L}$
(b) silane, $1.43 \mathrm{~g} / \mathrm{L}$
(c) nitric oxide, $1.34 \mathrm{~g} / \mathrm{L}$
(d) Freon- $22,3.86 \mathrm{~g} / \mathrm{L}$

Nicole Smina

Numerade Educator

Problem 29

Given $1 \mathrm{~mol}$ of each gas listed, complete the following table.

David Collins

Numerade Educator

Problem 30

Given 1 mol of each gas listed, complete the following table:

David Collins

Numerade Educator

Problem 31

Calculate the volume in liters for each of the following gases at STP:
(a) $0.250 \mathrm{~g}$ of helium, He
(b) $5.05 \mathrm{~g}$ of nitrogen, $\mathrm{N}_{2}$

David Collins

Numerade Educator

Problem 32

Calculate the volume in liters for each of the following gases at STP:
(a) $2.22 \times 10^{22}$ molecules of methane, $\mathrm{CH}_{4}$
(b) $4.18 \times 10^{24}$ molecules of ethane, $C_{2} H_{6}$

David Collins

Numerade Educator

Problem 33

Calculate the mass in grams for each of the following gases at STP:
(a) $1.05 \mathrm{~L}$ of hydrogen sulfide, $\mathrm{H}_{2} \mathrm{~S}$
(b) $5.33 \mathrm{~L}$ of dinitrogen trioxide, $\mathrm{N}_{2} \mathrm{O}_{3}$

David Collins

Numerade Educator

Problem 34

Calculate the mass in grams for each of the following gases at STP:
(a) $5.42 \times 10^{22}$ molecules of propane, $C_{3} H_{8}$
(b) $1.82 \times 10^{23}$ molecules of butane, $C_{4} H_{10}$

David Collins

Numerade Educator

Problem 35

Calculate the number of molecules in each of the following gases at STP:
(a) $100.0 \mathrm{~mL}$ of hydrogen, $\mathrm{H}_{2}$
(b) $70.5 \mathrm{~mL}$ of ammonia, $\mathrm{NH}_{3}$

David Collins

Numerade Educator

Problem 36

Calculate the number of molecules in each of the following gases at STP:
(a) $0.150 \mathrm{~g}$ of carbon monoxide, $\mathrm{CO}$
(b) $2.75 \mathrm{~g}$ of nitrogen monoxide, $\mathrm{NO}$

David Collins

Numerade Educator

Problem 37

Use the given quantity for each gas listed to complete the following table:

David Collins

Numerade Educator

Problem 38

Use the given quantity for each gas listed to complete the following table:

David Collins

Numerade Educator

Problem 39

If the percent hydrogen in a drop of water is $11 \%,$ what is the percent hydrogen in a kilogram of water?

David Collins

Numerade Educator

Problem 40

If the percent oxygen in a drop of water is $89 \%,$ what is the percent oxygen in a liter of water?

David Collins

Numerade Educator

Problem 41

Lactose is a sugar found in milk. Calculate the percent composition of lactose, $\mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11}$.

Nicole Smina

Numerade Educator

Problem 42

Benzoyl peroxide is the active ingredient in an acne cream. Calculate the percent composition of benzoyl peroxide, $\mathrm{C}_{14} \mathrm{H}_{10} \mathrm{O}_{4}$.

Nicole Smina

Numerade Educator

Problem 43

Methionine is an essential amino acid in protein. Calculate the percent composition of methionine, $\mathrm{C}_{5} \mathrm{H}_{11} \mathrm{NSO}_{2}$.

David Collins

Numerade Educator

Problem 44

Monosodium glutamate (MSG) is added to food to enhance the flavor. Calculate the percent composition of MSG, $\mathrm{NaC}_{5} \mathrm{H}_{8} \mathrm{NO}_{4}$.

David Collins

Numerade Educator

Problem 45

Mercurochrome dissolved in water is a reddish liquid formerly used as an antiseptic. Calculate the percent composition of mercurochrome, $\mathrm{HgNa}_{2} \mathrm{C}_{20} \mathrm{H}_{8} \mathrm{Br}_{2} \mathrm{O}_{6}$.

David Collins

Numerade Educator

Problem 46

Chlorophyll is a dark green plant pigment. Calculate the percent composition of chlorophyll, $\mathrm{C}_{55} \mathrm{H}_{70} \mathrm{MgN}_{4} \mathrm{O}_{6}$.

David Collins

Numerade Educator

Problem 47

In an experiment $0.500 \mathrm{~g}$ of tin reacted with nitric acid to give tin oxide. If the oxide had a mass of $0.635 \mathrm{~g}$, what is the empirical formula of tin oxide?

David Collins

Numerade Educator

Problem 48

In an experiment $0.500 \mathrm{~g}$ of nickel reacted with air to give 0.704 g of nickel oxide. What is the empirical formula of the oxide?

David Collins

Numerade Educator

Problem 49

In an experiment $2.410 \mathrm{~g}$ of copper oxide produced $1.925 \mathrm{~g}$ of copper metal after heating with hydrogen gas. What is the empirical formula of copper oxide?

David Collins

Numerade Educator

Problem 50

In an experiment $1.550 \mathrm{~g}$ of mercury oxide decomposed to give oxygen gas and $1.435 \mathrm{~g}$ of liquid mercury. What is the empirical formula of mercury oxide?

David Collins

Numerade Educator

Problem 51

A 1.115 g sample of cobalt was heated with sulfur to give $2.025 \mathrm{~g}$ of cobalt sulfide. What is the empirical formula of cobalt sulfide?

David Collins

Numerade Educator

Problem 52

A 0.715 g sample of titanium was heated with chlorine gas to give $2.836 \mathrm{~g}$ of titanium chloride. What is the empirical formula of titanium chloride?

David Collins

Numerade Educator

Problem 53

The percent composition of copper chloride is $64.1 \%$ Cu and $35.9 \%$ Cl. Calculate the empirical formula.

David Collins

Numerade Educator

Problem 54

The percent composition of vanadium oxide is $68.0 \% \mathrm{~V}$ and $32.0 \%$ O. Calculate the empirical formula.

Nicole Smina

Numerade Educator

Problem 55

The percent composition of tin bromide is $42.6 \% \mathrm{Sn}$ and $57.4 \%$ Br. Calculate the empirical formula.

David Collins

Numerade Educator

Problem 56

The percent composition of bismuth oxide is $89.7 \% \mathrm{Bi}$ and $10.3 \%$ O. Calculate the empirical formula.

David Collins

Numerade Educator

Problem 57

Trichloroethylene (TCE) is a common solvent used to degrease machine parts. Calculate the empirical formula for TCE if the percent composition is $18.25 \% \mathrm{C}, 0.77 \% \mathrm{H},$ and $80.99 \% \mathrm{Cl}$

David Collins

Numerade Educator

Problem 58

Dimethyl sulfoxide (DMSO) is a liniment for horses and has been used in the treatment of arthritis for humans. Calculate the empirical formula for DMSO, given that the percent composition is $30.7 \% \mathrm{C}, 7.74 \% \mathrm{H}, 20.5 \% \mathrm{O},$ and $41.0 \% \mathrm{~S}$.

David Collins

Numerade Educator

Problem 59

Aspirin has a molar mass of $180 \mathrm{~g} / \mathrm{mol}$. If the empirical formula is $\mathrm{C}_{9} \mathrm{H}_{8} \mathrm{O}_{4}$, what is the molecular formula of aspirin?

Nicole Smina

Numerade Educator

Problem 60

Quinine is used to treat malaria and has a molar mass of $325 \mathrm{~g} / \mathrm{mol}$. If the empirical formula is $\mathrm{C}_{10} \mathrm{H}_{12} \mathrm{NO},$ what is
the molecular formula of quinine?

Nicole Smina

Numerade Educator

Problem 61

Hexamethylene diamine is used to make nylon. If the molar mass is $115 \mathrm{~g} / \mathrm{mol}$ and the empirical formula is $\mathrm{C}_{3} \mathrm{H}_{8} \mathrm{~N}$, what is the molecular formula of the compound?

Nicole Smina

Numerade Educator

Problem 62

Adipic acid is used to make nylon. If the molar mass is $147 \mathrm{~g} / \mathrm{mol}$ and the empirical formula is $\mathrm{C}_{3} \mathrm{H}_{5} \mathrm{O}_{2}$, what is the molecular formula of the compound?

Nicole Smina

Numerade Educator

Problem 63

Ethylene glycol is used as permanent antifreeze. If the molar mass is $62 \mathrm{~g} / \mathrm{mol}$ and the percent composition is $38.7 \% \mathrm{C}$, $9.74 \% \mathrm{H},$ and $51.6 \% \mathrm{O},$ what is the molecular formula of ethylene glycol?

David Collins

Numerade Educator

Problem 64

ethylene glycol? Dioxane is a common solvent for plastics. If the molar mass is $88 \mathrm{~g} / \mathrm{mol}$ and the percent composition is $54.5 \% \mathrm{C}, 9.15 \% \mathrm{H}$, and $36.3 \% \mathrm{O}$, what is the molecular formula of dioxane?

David Collins

Numerade Educator

Problem 65

Lindane is an insecticide. If the molar mass is $290 \mathrm{~g} / \mathrm{mol}$ and the percent composition is $24.8 \% \mathrm{C}, 2.08 \% \mathrm{H},$ and $73.1 \% \mathrm{Cl}$ what is the molecular formula of lindane?

David Collins

Numerade Educator

Problem 66

Mercurous chloride is a fungicide. If the molar mass is $470 \mathrm{~g} / \mathrm{mol}$ and the percent composition is $85.0 \% \mathrm{Hg}$ and $15.0 \% \mathrm{Cl}$, what is the molecular formula of mercurous chloride?

David Collins

Numerade Educator

Problem 67

Nicotine has a molar mass of $160 \mathrm{~g} / \mathrm{mol}$. If the percent composition is $74.0 \% \mathrm{C}, 8.70 \% \mathrm{H},$ and $17.3 \% \mathrm{~N},$ what is the molecular formula of nicotine?

David Collins

Numerade Educator

Problem 68

Allose is a sugar with a molar mass of $180 \mathrm{~g} / \mathrm{mol}$. If the percent composition is $40.0 \% \mathrm{C}, 6.72 \% \mathrm{H},$ and $53.3 \% \mathrm{O},$ what is the molecular formula of allose?

David Collins

Numerade Educator

Problem 69

A quadrillion, $1 \times 10^{15}$, is the approximate number of red blood cells in 50,000 people. Which is greater: a quadrillion red blood cells or the number of nickel atoms in a $5-g$ nickel coin?

David Collins

Numerade Educator

Problem 70

By rubbing the Lincoln profile on a penny coin, a student removed just enough mass to be detected by an electronic balance, $0.0001 \mathrm{~g} .$ How many copper atoms were rubbed off the coin?

Nicole Smina

Numerade Educator

Problem 71

If the mass of Earth is $6 \times 10^{24} \mathrm{~kg}$ and an average rodent mole has a mass of $100 \mathrm{~g}$, which weighs more, Earth or a mole of furry moles?

David Collins

Numerade Educator

Problem 72

If a light year, $9.5 \times 10^{12} \mathrm{~km}$, is the distance light travels in a year and an average rodent mole has a length of $17 \mathrm{~cm}$, which is longer, a light year or a mole of furry moles?

David Collins

Numerade Educator

Problem 73

In 1871 Mendeleev predicted the undiscovered element ekaaluminum. In 1875 the element was discovered in Gaul (France) and was given the name gallium. If $0.500 \mathrm{~g}$ of gallium reacts with oxygen gas to give $0.672 \mathrm{~g}$ of gallium oxide, what is its empirical formula?

David Collins

Numerade Educator

Problem 74

In 1871 Mendeleev predicted the undiscovered element ekasilicon. In 1886 the element was discovered in Germany and was given the name germanium. If $0.500 \mathrm{~g}$ of germanium reacts with chlorine gas to give $1.456 \mathrm{~g}$ of germanium chloride, what is its empirical formula?

David Collins

Numerade Educator

Problem 75

Calculate the volume in cubic centimeters occupied by one molecule of water in a beaker of water. Recall that the density of water is $1.00 \mathrm{~g} / \mathrm{cm}^{3}$.

David Collins

Numerade Educator

Problem 76

Calculate the volume in milliliters occupied by one molecule of ethyl alcohol, $\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH},$ in a beaker of alcohol. The density of ethyl alcohol is $0.789 \mathrm{~g} / \mathrm{mL}$.

David Collins

Numerade Educator

Problem 77

Calculate the number of carbon atoms in $1.00 \mathrm{~g}$ of table sugar, $\mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11}$.

Nicole Smina

Numerade Educator

Problem 78

Calculate the number of carbon atoms in $1.00 \mathrm{~g}$ of blood sugar, $\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}$.

Nicole Smina

Numerade Educator

Problem 79

What is the mass of cuprite, $\mathrm{Cu}_{2} \mathrm{O}$, that contains $10.0 \mathrm{~g}$ of copper?

Nicole Smina

Numerade Educator

Problem 80

What is the mass of rust, $\mathrm{Fe}_{2} \mathrm{O}_{3}$, that contains $10.0 \mathrm{~g}$ of iron?

Nicole Smina

Numerade Educator

Problem 81

The volume occupied by each copper atom in a 1 -mole crystal is $0.0118 \mathrm{nm}^{3}$. If the density of the copper crystal is $8.92 \mathrm{~g} / \mathrm{cm}^{3},$ what is the experimental value of Avogadro's number?

Nicole Smina

Numerade Educator

Problem 82

Each atom in a crystal of aluminum metal occupies a theoretical cube that is $0.255 \mathrm{nm}$ on a side. If the density of the aluminum crystal is $2.70 \mathrm{~g} / \mathrm{cm}^{3},$ what is the experimental value of Avogadro's number?

David Collins

Numerade Educator

Problem 83

How many photons are in an Einstein?

Nicole Smina

Numerade Educator

Problem 84

How many electrons are in a Faraday?

Nicole Smina

Numerade Educator