Question 1

Calculate the percentage by mass of carbon in CO2.

Accepted Answer

A) 27.29 
B) 75.10 
C) 73.05 
D) 72.71 
E) 37.53 
A) 27.29 
B) 75.10 
C) 73.05 
D) 72.71 
E) 37.53

Question 2

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

Accepted Answer

A) 4, 50, 16, 18 
B) 1, 5, 2, 2 
C) 2, 2, 7, 1 
D) 1, 13, 8, 9 
E) 2, 25, 16, 18 
A) 4, 50, 16, 18 
B) 1, 5, 2, 2 
C) 2, 2, 7, 1 
D) 1, 13, 8, 9 
E) 2, 25, 16, 18

Question 3

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

Accepted Answer

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

Question 4

Combustion of a 0.9827-g sample of a compound containing only carbon,hydrogen,and oxygen produced 1.900 g of CO2 and 1.070 g of H2O.What is the empirical formula of the compound?

Accepted Answer

A) C2H5O 
B) C5H7O3 
C) C4H11O2 
D) C4H10O 
E) C2H5O2 
A) C2H5O 
B) C5H7O3 
C) C4H11O2 
D) C4H10O 
E) C2H5O2

Question 5

The combustion of propane (C3H8)in the presence of excess oxygen yields CO2 and H2O:
C3H8 (g)+ 5O2 (g)→ 3CO2 (g)+ 4H2O (g)
How many grams of CO2 is produced when 12.5 g of C3H8 burns in open air?

Accepted Answer

Question 6

What is the empirical formula of a compound that contains 49.4% K,20.3% S,and 30.3% O by mass?

Accepted Answer

A) KSO2 
B) KSO3 
C) K2SO4 
D) K2SO3 
E) KSO4 
A) KSO2 
B) KSO3 
C) K2SO4 
D) K2SO3 
E) KSO4

Question 7

A certain alcohol contains only three elements,carbon,hydrogen,and oxygen.Combustion of a 60.00 gram sample of the alcohol produced 114.6 grams of CO2 and 70.44 grams of H2O.What is the empirical formula of the alcohol?

Accepted Answer

Question 8

The combustion of ammonia in the presence of excess oxygen yields NO2 and H2O: 4 NH3 (g)+ 7 O2 (g)→ 4 NO2 (g)+ 6 H2O (g)
The combustion of 14.4 g of ammonia consumes ________ g of oxygen.

Accepted Answer

A) 13.5 
B) 28.8 
C) 54.1 
D) 47.3 
E) 94.6 
A) 13.5 
B) 28.8 
C) 54.1 
D) 47.3 
E) 94.6

Question 9

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

Accepted Answer

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

Question 10

The molecular formula of aspartame,the generic name of NutraSweet®,is C14H18N2O5.What is the mass (g)of 1.00 mol of aspartame?

Accepted Answer

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

Question 11

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

Accepted Answer

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

Question 12

GeF3H is formed from GeH4 and GeF4 in the combination reaction: GeH4 + 3GeF4 → 4GeF3H
If the reaction yield is 89.1%,how many moles of GeH4 are needed to produce 3.50 mol of GeF3H?

Accepted Answer

A) 15.7 
B) 3.93 
C) 0.982 
D) 0.875 
E) 2.95 
A) 15.7 
B) 3.93 
C) 0.982 
D) 0.875 
E) 2.95

Question 13

A compound that is composed of only carbon and hydrogen contains 85.7% C and 14.3% H by mass.What is the empirical formula of the compound?

Accepted Answer

A) CH2 
B) C2H4 
C) CH4 
D) C4H8 
E) C86H14 
A) CH2 
B) C2H4 
C) CH4 
D) C4H8 
E) C86H14

Question 14

1 mole of which of the following will have the largest mass?

Accepted Answer

A) rubidium 
B) magnesium 
C) gold 
D) neon 
E) 1 mole of any element will contain the same mass. 
A) rubidium 
B) magnesium 
C) gold 
D) neon 
E) 1 mole of any element will contain the same mass.

Question 15

Lithium and nitrogen react in a combination reaction to produce lithium nitride: 6Li (s)+ N2 (g)→ 2Li3N (s)
In a particular experiment,2.50-g samples of each reagent are reacted.The theoretical yield of lithium nitride is ________ g.

Accepted Answer

A) 2.51 
B) 2.09 
C) 12.5 
D) 4.18 
E) 6.2 
A) 2.51 
B) 2.09 
C) 12.5 
D) 4.18 
E) 6.2

Question 16

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

Accepted Answer

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 
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

Question 17

The formula weight of PbCO3 is ________ amu.

Accepted Answer

A) 279.2 
B) 112.0 
C) 118.0 
D) 267.2 
E) 235.2 
A) 279.2 
B) 112.0 
C) 118.0 
D) 267.2 
E) 235.2

Question 18

Lead (II)carbonate decomposes to give lead (II)oxide and carbon dioxide: PbCO3 (s)→ PbO (s)+ CO2 (g)
________ grams of lead (II)oxide will be produced by the decomposition of 8.75 g of lead (II)carbonate?

Accepted Answer

A) 10.5 
B) 2.50 
C) 0.033 
D) 7.31 
E) 8.75 
A) 10.5 
B) 2.50 
C) 0.033 
D) 7.31 
E) 8.75

Question 19

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

Accepted Answer

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

Question 20

Lithium and nitrogen react in a combination reaction to produce lithium nitride: 6Li (s)+ N2 (g)→ 2Li3N (s)
How many moles of lithium are needed to produce 0.45 mol of Li3N when the reaction is carried out in the presence of excess nitrogen?

Accepted Answer

A) 0.23 
B) 1.4 
C) 0.15 
D) 0.30 
E) 2.7 
A) 0.23 
B) 1.4 
C) 0.15 
D) 0.30 
E) 2.7

Exam 3: Chemical Reactions and Reaction Stoichiometry

Calculate the percentage by mass of carbon in CO2.

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

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

Combustion of a 0.9827-g sample of a compound containing only carbon,hydrogen,and oxygen produced 1.900 g of CO2 and 1.070 g of H2O.What is the empirical formula of the compound?

The combustion of propane (C3H8)in the presence of excess oxygen yields CO2 and H2O: C3H8 (g)+ 5O2 (g)→ 3CO2 (g)+ 4H2O (g) How many grams of CO2 is produced when 12.5 g of C3H8 burns in open air?

What is the empirical formula of a compound that contains 49.4% K,20.3% S,and 30.3% O by mass?

A certain alcohol contains only three elements,carbon,hydrogen,and oxygen.Combustion of a 60.00 gram sample of the alcohol produced 114.6 grams of CO2 and 70.44 grams of H2O.What is the empirical formula of the alcohol?

The combustion of ammonia in the presence of excess oxygen yields NO2 and H2O: 4 NH3 (g)+ 7 O2 (g)→ 4 NO2 (g)+ 6 H2O (g) The combustion of 14.4 g of ammonia consumes ________ g of oxygen.

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

The molecular formula of aspartame,the generic name of NutraSweet®,is C14H18N2O5.What is the mass (g)of 1.00 mol of aspartame?

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

GeF3H is formed from GeH4 and GeF4 in the combination reaction: GeH4 + 3GeF4 → 4GeF3H If the reaction yield is 89.1%,how many moles of GeH4 are needed to produce 3.50 mol of GeF3H?

A compound that is composed of only carbon and hydrogen contains 85.7% C and 14.3% H by mass.What is the empirical formula of the compound?

1 mole of which of the following will have the largest mass?

Lithium and nitrogen react in a combination reaction to produce lithium nitride: 6Li (s)+ N2 (g)→ 2Li3N (s) In a particular experiment,2.50-g samples of each reagent are reacted.The theoretical yield of lithium nitride is ________ g.

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

The formula weight of PbCO3 is ________ amu.

Lead (II)carbonate decomposes to give lead (II)oxide and carbon dioxide: PbCO3 (s)→ PbO (s)+ CO2 (g) ________ grams of lead (II)oxide will be produced by the decomposition of 8.75 g of lead (II)carbonate?

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

Lithium and nitrogen react in a combination reaction to produce lithium nitride: 6Li (s)+ N2 (g)→ 2Li3N (s) How many moles of lithium are needed to produce 0.45 mol of Li3N when the reaction is carried out in the presence of excess nitrogen?

Introduction: Matter, energy, and Measurement

Atoms, molecules, and Ions

Reactions in Aqueous Solution

Thermochemistry

Electronic Structure of Atoms

Periodic Properties of the Elements

Basic Concepts of Chemical Bonding

Molecular Geometry and Bonding Theories

Gases

Liquids and Intermolecular Forces

Solids and Modern Materials

Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Acid-Base Equilibria

Additional Aspects of Aqueous Equilibria

Chemistry of the Environment

Chemical Thermodynamics

Electrochemistry

Nuclear Chemistry

Chemistry of the Nonmetals

Transition Metals and Coordination Chemistry

The Chemistry of Life: Organic and Biological Chemistry

Filters

Calculate the percentage by mass of carbon in CO₂.

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

Combustion of a 0.9827-g sample of a compound containing only carbon,hydrogen,and oxygen produced 1.900 g of CO₂ and 1.070 g of H₂O.What is the empirical formula of the compound?

The combustion of propane (C₃H₈)in the presence of excess oxygen yields CO₂ and H₂O: C₃H₈ (g)+ 5O₂ (g)→ 3CO₂(g)+ 4H₂O (g) How many grams of CO₂ is produced when 12.5 g of C₃H₈ burns in open air?

A certain alcohol contains only three elements,carbon,hydrogen,and oxygen.Combustion of a 60.00 gram sample of the alcohol produced 114.6 grams of CO₂ and 70.44 grams of H₂O.What is the empirical formula of the alcohol?

The combustion of ammonia in the presence of excess oxygen yields NO₂ and H₂O: 4 NH₃ (g)+ 7 O₂ (g)→ 4 NO₂ (g)+ 6 H₂O (g) The combustion of 14.4 g of ammonia consumes ________ g of oxygen.

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

The molecular formula of aspartame,the generic name of NutraSweet^®,is C₁₄H₁₈N₂O_5.What is the mass (g)of 1.00 mol of aspartame?

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

GeF₃H is formed from GeH₄ and GeF₄in the combination reaction: GeH₄ + 3GeF₄ → 4GeF₃H If the reaction yield is 89.1%,how many moles of GeH₄ are needed to produce 3.50 mol of GeF₃H?

Lithium and nitrogen react in a combination reaction to produce lithium nitride: 6Li (s)+ N₂(g)→ 2Li₃N (s) In a particular experiment,2.50-g samples of each reagent are reacted.The theoretical yield of lithium nitride is ________ g.

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

The formula weight of PbCO₃ is ________ amu.

Lead (II)carbonate decomposes to give lead (II)oxide and carbon dioxide: PbCO₃(s)→ PbO (s)+ CO₂(g) ________ grams of lead (II)oxide will be produced by the decomposition of 8.75 g of lead (II)carbonate?

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

Lithium and nitrogen react in a combination reaction to produce lithium nitride: 6Li (s)+ N₂(g)→ 2Li₃N (s) How many moles of lithium are needed to produce 0.45 mol of Li₃N when the reaction is carried out in the presence of excess nitrogen?