Deck 3: Stoichiometry: Calculations With Chemical Formulas and Equations

Question 1

The formula weight of potassium phosphate (K₃PO₄)is __________ amu.

A)173.17
B)251.37
C)212.27
D)196.27
E)86.07

Answer 1

212.27

Question 2

The molecular weight of the ethanol (C₂H₅OH), rounded to the nearest integer, is __________ amu.

A)34
B)41
C)30
D)46
E)92

Answer 2

46

Question 3

Which of the following are decomposition reactions? 1)CH₄ (g)+ O₂ (g)→ CO₂ (g)+ H₂O (l)
2)CaO (s)+ CO₂ (g)→ CaCO₃ (s)
3)Mg (s)+ O₂ (g)→ MgO (s)
4)PbCO₃ (s)→ PbO (s)+ CO₂ (g)

A)1, 2, and 3
B)4 only
C)1, 2, 3, and 4
D)2 and 3
E)2, 3, and 4

Answer 3

4 only

Question 4

The formula weight of lead (II)carbonate (PbCO₃)is __________ amu.

A)207.2
B)219.2
C)235.2
D)267.2
E)273.2

Question 5

When the following equation is balanced, the coefficients are __________. C₈H₁₈ + O₂ → CO₂ + H₂O

A)2, 3, 4, 4
B)1, 4, 8, 9
C)2, 12, 8, 9
D)4, 4, 32, 36
E)2, 25, 16, 18

Question 6

Of the reactions below, which one is not a combination reaction?

A)C + O₂ → CO₂
B)2Mg + O₂ → 2MgO
C)2N₂ + 3H₂ → 2NH₃
D)CaO + H₂O → Ca(OH)₂
E)2CH₄ + 4O₂ → 2CO₂ + 4H₂O

Question 7

When a hydrocarbon burns in air, a component produced is?

A)oxygen
B)nitrogen
C)carbon
D)water
E)argon

Question 8

Of the reactions below, which one is a decomposition reaction?

A)NH₄Cl → NH₃ + HCl
B)2Mg + O₂ → 2MgO
C)2N₂ + 3 H₂ → 2NH₃
D)2CH₄ + 4O₂ → 2CO₂ + 4H₂O
E)Cd(NO₃)O₂ + Na₂S → CdS + 2NaNO₃

Question 9

The formula weight of potassium dichromate (K₂Cr₂O₇)is __________ amu.

A)107.09
B)255.08
C)242.18
D)294.18
E)333.08

Question 10

Which of the following are combination reactions? 1)CH₄ (g)+ O₂ (g)→ CO₂ (g)+ H₂O (l)
2)CaO (s)+ CO₂ (g)→ CaCO₃ (s)
3)Mg (s)+ O₂ (g)→ MgO (s)
4)PbCO₃ (s)→ PbO (s)+ CO₂ (g)

A)1, 2, and 3
B)2 and 3
C)1, 2, 3, and 4
D)4 only
E)2, 3, and 4

Question 11

When a hydrocarbon burns in air, what component of air reacts?

A)oxygen
B)nitrogen
C)carbon dioxide
D)water
E)argon

Question 12

The formula weight of silver chromate (Ag₂CrO₄)is __________ amu.

A)159.87
B)223.87
C)331.73
D)339.86
E)175.87

Question 13

Which one of the following substances is the product of this combination reaction? Al (s)+ I₂ (s)→ __________

A)AlI₂
B)AlI
C)AlI₃
D)Al₂I₃
E)Al₃I₂

Question 14

Which one of the following is not true concerning automotive air bags?

A)They are inflated as a result of a decomposition reaction
B)They are loaded with sodium azide initially
C)The gas used for inflating them is oxygen
D)The two products of the decomposition reaction are sodium and nitrogen
E)A gas is produced when the air bag activates.

Question 15

The molecular weight of the acetic acid (CH₃CO₂H), rounded to the nearest integer, is __________ amu.

A)60
B)48
C)44
D)32

Question 16

The formula weight of ammonium sulfate ((NH₄)O₂SO₄), rounded to the nearest integer, is __________ amu.

A)100
B)118
C)116
D)132
E)264

Question 17

Which of the following are combustion reactions?
1)CH₄ (g)+ O₂ (g)→ CO₂ (g)+ H₂O (l)
2)CaO (s)+ CO₂ (g)→ CaCO₃ (s)
3)PbCO₃ (s)→ PbO (s)+ CO₂ (g)
4)CH₃OH (l)+ O₂ (g)→ CO₂ (g)+ H₂O (l)

A)1 and 4
B)1, 2, 3, and 4
C)1, 3, and 4
D)2, 3, and 4
E)3 and 4

Question 18

The formula of nitrobenzene is C₆H₅N O₂. The molecular weight of this compound is __________ amu.

A)107.11
B)43.03
C)109.10
D)123.11
E)3.06

Question 19

The formula weight of aluminum sulfate (Al₂(SO₄)₃)is __________ amu.

A)342.15
B)123.04
C)59.04
D)150.14
E)273.06

Question 20

The reaction used to inflate automobile airbags __________.

A)produces sodium gas
B)is a combustion reaction
C)is a combination reaction
D)violates the law of conservation of mass
E)is a decomposition reaction

Question 21

Calculate the percentage by mass of chlorine in PtCl₂(NH₃)₂.

A)23.63
B)11.82
C)25.05
D)12.53
E)18.09

Question 22

Calculate the percentage by mass of lead in Pb(NO₃)₂.

A)38.6
B)44.5
C)62.6
D)65.3
E)71.2

Question 23

The formula weight of calcium nitrate (Ca(NO₃)₂), rounded to one decimal place, is __________ amu.

A)102.1
B)164.0
C)204.2
D)150.1
E)116.1

Question 24

The mass % of Al in aluminum sulfate (Al₂(SO₄)₃)is __________.

A)7.886
B)15.77
C)21.93
D)45.70
E)35.94

Question 25

The formula weight of lead nitrate (Pb(NO₃)₂)is __________ amu.

A)269.2
B)285.2
C)317.2
D)331.2
E)538.4

Question 26

Calculate the percentage by mass of lead in PbCO₃.

A)17.96
B)22.46
C)73.05
D)77.54
E)89.22

Question 27

The formula weight of a substance is __________.

A)identical to the molar mass
B)the same as the percent by mass weight
C)determined by combustion analysis
D)the sum of the atomic weights of each atom in its chemical formula
E)the weight of a sample of the substance

Question 28

The molecular weight of glucose (C₆H₁₂O₆), rounded to the nearest integer, is __________ amu.

A)24
B)96
C)136
D)180
E)224

Question 29

Calculate the percentage by mass of oxygen in Pb(NO₃)₂.

A)9.7
B)14.5
C)19.3
D)29.0
E)33.4

Question 30

The mass % of H in methane (CH₄)is __________.

A)25.13
B)4.032
C)74.87
D)92.26
E)7.743

Question 31

One mole of __________ contains the smallest number of atoms.

A)S₈
B)C₁₀H₈
C)Al₂(SO₄)₃
D)Na₃PO₄
E)NaCl

Question 32

The mass % of C in methane (CH₄)is __________.

A)25.13
B)133.6
C)74.87
D)92.26
E)7.743

Question 33

The formula weight of magnesium fluoride (MgF₂), rounded to one decimal place, is __________ amu.

A)86.6
B)43.3
C)62.3
D)67.6
E)92.9

Question 34

Calculate the percentage by mass of nitrogen in Pb(NO₃)₂.

A)4.2
B)5.2
C)8.5
D)10.4
E)12.6

Question 35

Calculate the percentage by mass of hydrogen in PtCl₂(N H₃)₂

A)1.558
B)1.008
C)0.672
D)0.034
E)2.016

Question 36

What is the mass % of carbon in dimethylsulfoxide (C₂H₆SO)rounded to three significant figures?

A)60.0
B)20.6
C)30.7
D)7.74
E)79.8

Question 37

The mass % of F in the binary compound KrF₂ is __________.

A)18.48
B)45.38
C)68.80
D)81.52
E)31.20

Question 38

One mole of __________ contains the largest number of atoms.

A)S₈
B)C₁₀H₈
C)Al₂(SO₄)₃
D)Na₃PO₄
E)Cl₂

Question 39

Calculate the percentage by mass of nitrogen in PtCl₂(NH₃)₂.

A)4.67
B)9.34
C)9.90
D)4.95
E)12.67

Question 40

One million argon atoms is __________ mol (rounded to two significant figures)of argon atoms.

A)3.0
B)1.7 × 10^-18
C)6.0 × 10²³
D)1.0 × 10^-6
E)1.0 × 10⁺⁶

Question 41

How many moles of sodium carbonate contain 1.773 × 10¹⁷ carbon atoms?

A)5.890 × 10^-7
B)2.945 × 10^-7
C)1.473 × 10^-7
D)8.836 × 10^-7
E)9.817 × 10^-8

Question 42

How many moles of pyridine (C₅H₅N)are contained in 3.13 g of pyridine?

A)0.0396
B)25.3
C)0.319
D)0.00404
E)4.04 × 10³

Question 43

How many sulfur dioxide molecules are there in 0.180 mol of sulfur dioxide?

A)1.80 × 10²³
B)6.02 × 10²⁴
C)6.02 × 10²³
D)1.08 × 10²⁴
E)1.08 × 10²³

Question 44

How many sulfur dioxide molecules are there in 1.80 mol of sulfur dioxide?

A)1.08 × 10²³
B)6.02 × 10²⁴
C)1.80 × 10²⁴
D)1.08 × 10²⁴
E)6.02 × 10²³

Question 45

How many carbon atoms are there in 52.06 g of carbon dioxide?

A)5.206 × 10²⁴
B)3.134 × 10²⁵
C)7.122 × 10²³
D)8.648 × 10^-23
E)1.424 × 10²⁴

Question 46

How many oxygen atoms are contained in 2.74 g of Al₂(SO₄)₃?

A)12
B)6.02 × 10²³
C)7.22 × 10²⁴
D)5.79 × 10²²
E)8.01 × 10^-3

Question 47

There are __________ atoms of oxygen are in 300 molecules of CH₃CO₂H.

A)300
B)600
C)3.01 × 10²⁴
D)3.61 × 10²⁶
E)1.80 × 10²⁶

Question 48

Gaseous argon has a density of 1.40 g/L at standard conditions. How many argon atoms are in 1.00 L of argon gas at standard conditions?

A)4.76 × 10²²
B)3.43 × 10²⁶
C)2.11 × 10²²
D)1.59 × 10²⁵
E)6.02 × 10²³

Question 49

A 30.5 gram sample of glucose (C₆H₁₂O₆)contains __________ atoms of carbon.

A)1.02 x 10²³
B)6.12 x 10²³
C)6.02 x 10²³
D)2.04 x 10²³
E)1.22 x 10²⁴

Question 50

How many oxygen atoms are there in 52.06 g of carbon dioxide?

A)1.424 × 10²⁴
B)6.022 × 10²³
C)1.204 × 10²⁴
D)5.088 × 10²³
E)1.018 × 10²⁴

Question 51

What is the mass in grams of 9.76 × 10¹² atoms of naturally occurring sodium?

A)22.99
B)1.62 × 10^-11
C)3.73 × 10^-10
D)7.05 × 10^-13
E)2.24 × 10¹⁴

Question 52

How many atoms of nitrogen are in 10 g of NH₄NO₃?

A)3.5
B)1.5 × 10²³
C)3.0 × 10²³
D)1.8
E)2

Question 53

A sample of CH₂F₂ with a mass of 19 g contains __________ atoms of F.

A)2.2 × 10²³
B)38
C)3.3 × 10²⁴
D)4.4 × 10²³
E)9.5

Question 54

A 30.5 gram sample of glucose (C₆H₁₂O₆)contains __________ mol of glucose.

A)0.424
B)0.169
C)5.90
D)2.36
E)0.136

Question 55

How many grams of sodium carbonate contain 1.773 × 10¹⁷ carbon atoms?

A)3.121 × 10^-5
B)1.011 × 10^-5
C)1.517 × 10^-5
D)9.100 × 10^-5
E)6.066 × 10^-5

Question 56

How many molecules of CH₄ are in 48.2 g of this compound?

A)5.00 × 10²⁴
B)3.00
C)2.90 × 10²⁵
D)1.81 × 10²⁴
E)4.00

Question 57

The molecular formula of aspartame, the generic name of NutraSweet^®, is C₁₄H₁₈N₂O₅. The molar mass of aspartame, rounded to the nearest integer, is __________ g.

A)24
B)156
C)294
D)43
E)39

Question 58

The compound responsible for the characteristic smell of garlic is allicin, C₆H₁₀OS₂. The mass of 1.00 mol of allicin, rounded to the nearest integer, is __________ g.

A)34
B)162
C)86
D)61
E)19

Question 59

The total number of atoms in 0.111 mol of Fe(CO)₃(PH₃)₂ is __________.

A)15.0
B)1.00 × 10²⁴
C)4.46 × 10²¹
D)1.67
E)2.76 × 10^-24

Question 60

A sample of CH₄O with a mass of 32.0 g contains __________ molecules of CH₄O.

A)5.32 × 10^-23
B)1.00
C)1.88 × 10²²
D)6.02 × 10²³
E)32.0

Question 61

When the following equation is balanced, the coefficient of C₃H₈O₃ is __________. C₃H₈O₃ (g)+ O₂ (g)→ CO₂ (g)+ H₂O (g)

A)1
B)2
C)3
D)7
E)5

Question 62

When the following equation is balanced, the coefficient of H₃PO₄ is __________. H₃PO₄ (aq)+ NaOH (aq)→ Na₃PO₄ (aq)+ H₂O (l)

A)1
B)2
C)3
D)4
E)0

Question 63

When the following equation is balanced, the coefficient of Al₂O₃ is __________. Al₂O₃ (s)+ C (s)+ Cl₂ (g)→ AlCl₃ (s)+ CO (g)

A)1
B)2
C)3
D)4
E)5

Question 64

When the following equation is balanced, the coefficient of H₂ is __________. K (s)+ H₂O (l)→ KOH (aq)+ H₂ (g)

A)1
B)2
C)3
D)4
E)5

Question 65

There are ________ oxygen atoms in 30 molecules of C₂₀H₄₂S₃O₂.

A)6.0 x 10²³
B)1.8 x 10²⁵
C)3.6 x 10²⁵
D)1.2 x 10²⁴
E)60

Question 66

Which hydrocarbon pair below have identical mass percentage of C?

A)C₃H₄ and C₃H₆
B)C₂H₄ and C₃H₄
C)C₂H₄ and C₄H₂
D)C₂H₄ and C₃H₆
E)none of the above

Question 67

When the following equation is balanced, the coefficient of Al is __________. Al (s)+ H₂O (l)→ Al(OH)₃ (s)+ H₂ (g)

A)1
B)2
C)3
D)5
E)4

Question 68

When the following equation is balanced, the coefficient of H₂S is __________. FeCl₃ (aq)+ H₂S (g)→ Fe₂S₃ (s)+ HCl (aq)

A)1
B)2
C)3
D)5
E)4

Question 69

A sulfur oxide is 50.0% by mass sulfur. This molecular formula could be __________.

A)SO
B)SO₂
C)S₂O
D)S₂O₄
E)either SO₂ or S₂O₄

Question 70

When the following equation is balanced, the coefficient of H₂SO₄ is __________. H₂SO₄ (aq)+ NaOH (aq)→ Na₂SO₄ (aq)+ H₂O (l)

A)1
B)2
C)3
D)4
E)0.5

Question 71

When the following equation is balanced, the coefficient of HNO₃ is __________. HNO₃ (aq)+ CaCO₃ (s)→ Ca(NO₃)₂ (aq)+ CO₂ (g)+ H₂O (l)

A)1
B)2
C)3
D)5
E)4

Question 72

Propane (C₃H₈)reacts with oxygen in the air to produce carbon dioxide and water. In a particular experiment, 38.0 grams of carbon dioxide are produced from the reaction of 22.05 grams of propane with excess oxygen. What is the % yield in this reaction?

A)38.0
B)57.6
C)66.0
D)86.4
E)94.5

Question 73

Sulfur and oxygen react to produce sulfur trioxide. In a particular experiment, 7.9 grams of SO₃ are produced by the reaction of 5.0 grams of O₂ with 6.0 grams of S. What is the % yield of SO₃ in this experiment? S (s)+ O₂ (g)→ SO₃ (g)(not balanced)

A)32
B)63
C)75
D)95
E)99

Question 74

When the following equation is balanced, the coefficient of HCl is __________. CaCO₃ (s)+ HCl (aq)→ CaCl₂ (aq)+ CO₂ (g)+ H₂O (l)

A)1
B)2
C)3
D)4
E)0

Question 75

A nitrogen oxide is 63.65% by mass nitrogen. The molecular formula could be __________.

A)NO
B)NO₂
C)N₂O
D)N₂O₄
E)either NO₂ or N₂O₄

Question 76

When the following equation is balanced, the coefficient of H₂ is __________. CO (g)+ H₂ (g)→ H₂O (g)+ CH₄ (g)

A)1
B)2
C)3
D)4
E)0

Question 77

When the following equation is balanced, the coefficient of H₂O is __________. Ca (s)+ H₂O (l)→ Ca(OH)₂ (aq)+ H₂ (g)

A)1
B)2
C)3
D)5
E)4

Question 78

When the following equation is balanced, the coefficients are __________. NH₃ (g)+ O₂ (g)→ NO₂ (g)+ H₂O (g)

A)1, 1, 1, 1
B)4, 7, 4, 6
C)2, 3, 2, 3
D)1, 3, 1, 2
E)4, 3, 4, 3

Question 79

When the following equation is balanced, the coefficient of O₂ is __________. C₂H₄O (g)+ O₂ (g)→ CO₂ (g)+ H₂O (g)

A)2
B)3
C)4
D)5
E)1

Question 80

When the following equation is balanced, the coefficients are __________. Al(NO₃)₃ + Na₂S → Al₂S₃ + NaNO₃

A)2, 3, 1, 6
B)2, 1, 3, 2
C)1, 1, 1, 1
D)4, 6, 3, 2
E)2, 3, 2, 3