Question 1

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

Accepted Answer

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

Question 2

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

Accepted Answer

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

Question 3

There are __________ molecules of methane in 0.123 mol of methane (CH4).

Accepted Answer

A) 5 
B) 2.46 × 10-2 
C) 2.04 × 10-25 
D) 7.40 × 1022 
E) 0.615 
A) 5 
B) 2.46 × 10-2 
C) 2.04 × 10-25 
D) 7.40 × 1022 
E) 0.615

Question 4

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 5

Lead (II)carbonate decomposes to give lead (II)oxide and carbon dioxide: PbCO3 (s)→ PbO (s)+ CO2 (g)
How many grams of lead (II)oxide will be produced by the decomposition of 2.50 g of lead (II)carbonate?

Accepted Answer

A) 0.41 
B) 2.50 
C) 0.00936 
D) 2.09 
E) 2.61 
A) 0.41 
B) 2.50 
C) 0.00936 
D) 2.09 
E) 2.61

Question 6

The reaction used to inflate automobile airbags __________.

Accepted Answer

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 
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 7

The combustion of carbon disulfide in the presence of excess oxygen yields carbon dioxide and sulfur dioxide:
CS2 (g)+ 3O2 (g)→ CO2 (g)+ 2SO2 (g)
The combustion of 15 g of CS2 in the presence of excess oxygen yields __________ g of SO2.

Accepted Answer

Question 8

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)

Accepted Answer

A) 1 and 4 
B) 1, 2, 3, and 4 
C) 1, 3, and 4 
D) 2, 3, and 4 
E) 3 and 4 
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 9

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 0.20 mol of Li3N when the reaction is carried out in the presence of excess nitrogen?

Accepted Answer

A) 0.10 
B) 0.60 
C) 0.067 
D) 0.13 
E) 1.2 
A) 0.10 
B) 0.60 
C) 0.067 
D) 0.13 
E) 1.2

Question 10

How many moles of magnesium oxide are produced by the reaction of 3.82 g of magnesium nitride with 7.73 g of water? Mg3N2 + 3 H2O → 2NH3 + 3MgO

Accepted Answer

A) 0.114 
B) 0.0378 
C) 0.429 
D) 0.0756 
E) 4.57 
A) 0.114 
B) 0.0378 
C) 0.429 
D) 0.0756 
E) 4.57

Question 11

How many moles of carbon monoxide are there in 36.55 g of carbon monoxide?

Accepted Answer

A) 0.8452 
B) 1.305 
C) 0.9291 
D) 2.589 
E) 3.046 
A) 0.8452 
B) 1.305 
C) 0.9291 
D) 2.589 
E) 3.046

Question 12

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

Accepted Answer

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

Question 13

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

Accepted Answer

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

Question 14

Magnesium burns in air with a dazzling brilliance to produce magnesium oxide: 2Mg (s)+ O2 (g)→ 2MgO (s)
How many moles of O2 are consumed when 4.11 mol of magnesium burns?

Accepted Answer

A) 0.169 
B) 0.487 
C) 4.11 
D) 8.22 
E) 2.06 
A) 0.169 
B) 0.487 
C) 4.11 
D) 8.22 
E) 2.06

Question 15

Calcium carbide (CaC2)reacts with water to produce acetylene (C2H2): CaC2 (s)+ 2 H2O (g)→ Ca(OH)2 (s)+ C2H2 (g)
Production of 3.3 g of C2H2 requires consumption of __________ g of H2O.

Accepted Answer

A) 1.2 
B) 2.3 
C) 4.6 
D) 480 
E) 0.048 
A) 1.2 
B) 2.3 
C) 4.6 
D) 480 
E) 0.048

Question 16

There are __________ mol of carbon atoms in 3 mol of dimethylsulfoxide (C2H6SO).

Accepted Answer

A) 2 
B) 4 
C) 6 
D) 8 
E) 10 
A) 2 
B) 4 
C) 6 
D) 8 
E) 10

Question 17

Predict the product in the combination reaction below. Al (s)+ N2 (g)→ __________

Accepted Answer

A) AlN 
B) Al3N 
C) Al N2 
D) Al3N2 
E) AlN3 
A) AlN 
B) Al3N 
C) Al N2 
D) Al3N2 
E) AlN3

Question 18

A great deal of the carbon dioxide produced by the combustion of fossil fuels is absorbed into the oceans.

Accepted Answer

A) True 
 B)False

Question 19

The combustion of propane (C3H8)produces CO2 and H2O: C3H8 (g)+ 5 O2 (g)→ 3CO2 (g)+ 4 H2O (g)
The reaction of 2.5 mol of O2 with 4.6 mol of C3H8 will produce __________ mol of H2O.

Accepted Answer

A) 4.0 
B) 3.0 
C) 2.5 
D) 2.0 
E) 1.0 
A) 4.0 
B) 3.0 
C) 2.5 
D) 2.0 
E) 1.0

Question 20

Sulfur and fluorine react in a combination reaction to produce sulfur hexafluoride: S (s)+ 3 F3 (g)→ SF6 (g)
The maximum amount of SF6 that can be produced from the reaction of 3.5 g of sulfur with 4.5 g of fluorine is __________ g.

Accepted Answer

A) 12 
B) 3.2 
C) 5.8 
D) 16 
E) 8.0 
A) 12 
B) 3.2 
C) 5.8 
D) 16 
E) 8.0

Exam 3: Stoichiometry: Calculations With Chemical Formulas and Equations

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

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

There are __________ molecules of methane in 0.123 mol of methane (CH4).

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

Lead (II)carbonate decomposes to give lead (II)oxide and carbon dioxide: PbCO3 (s)→ PbO (s)+ CO2 (g) How many grams of lead (II)oxide will be produced by the decomposition of 2.50 g of lead (II)carbonate?

The reaction used to inflate automobile airbags __________.

The combustion of carbon disulfide in the presence of excess oxygen yields carbon dioxide and sulfur dioxide: CS2 (g)+ 3O2 (g)→ CO2 (g)+ 2SO2 (g) The combustion of 15 g of CS2 in the presence of excess oxygen yields __________ g of SO2.

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)

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 0.20 mol of Li3N when the reaction is carried out in the presence of excess nitrogen?

How many moles of magnesium oxide are produced by the reaction of 3.82 g of magnesium nitride with 7.73 g of water? Mg3N2 + 3 H2O → 2NH3 + 3MgO

How many moles of carbon monoxide are there in 36.55 g of carbon monoxide?

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

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

Magnesium burns in air with a dazzling brilliance to produce magnesium oxide: 2Mg (s)+ O2 (g)→ 2MgO (s) How many moles of O2 are consumed when 4.11 mol of magnesium burns?

Calcium carbide (CaC2)reacts with water to produce acetylene (C2H2): CaC2 (s)+ 2 H2O (g)→ Ca(OH)2 (s)+ C2H2 (g) Production of 3.3 g of C2H2 requires consumption of __________ g of H2O.

There are __________ mol of carbon atoms in 3 mol of dimethylsulfoxide (C2H6SO).

Predict the product in the combination reaction below. Al (s)+ N2 (g)→ __________

A great deal of the carbon dioxide produced by the combustion of fossil fuels is absorbed into the oceans.

The combustion of propane (C3H8)produces CO2 and H2O: C3H8 (g)+ 5 O2 (g)→ 3CO2 (g)+ 4 H2O (g) The reaction of 2.5 mol of O2 with 4.6 mol of C3H8 will produce __________ mol of H2O.

Sulfur and fluorine react in a combination reaction to produce sulfur hexafluoride: S (s)+ 3 F3 (g)→ SF6 (g) The maximum amount of SF6 that can be produced from the reaction of 3.5 g of sulfur with 4.5 g of fluorine is __________ g.

Introduction: Matter and Measurement

Atoms, Molecules, and Ions

Aqueous Reactions and Solution Stoichiometry

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

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

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

There are __________ molecules of methane in 0.123 mol of methane (CH₄).

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

Lead (II)carbonate decomposes to give lead (II)oxide and carbon dioxide: PbCO₃ (s)→ PbO (s)+ CO₂ (g) How many grams of lead (II)oxide will be produced by the decomposition of 2.50 g of lead (II)carbonate?

The combustion of carbon disulfide in the presence of excess oxygen yields carbon dioxide and sulfur dioxide: CS₂ (g)+ 3O₂ (g)→ CO₂ (g)+ 2SO₂ (g) The combustion of 15 g of CS₂ in the presence of excess oxygen yields __________ g of SO₂.

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)

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 0.20 mol of Li₃N when the reaction is carried out in the presence of excess nitrogen?

How many moles of magnesium oxide are produced by the reaction of 3.82 g of magnesium nitride with 7.73 g of water? Mg₃N₂ + 3 H₂O → 2NH₃ + 3MgO

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

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

Magnesium burns in air with a dazzling brilliance to produce magnesium oxide: 2Mg (s)+ O₂ (g)→ 2MgO (s) How many moles of O₂ are consumed when 4.11 mol of magnesium burns?

Calcium carbide (CaC₂)reacts with water to produce acetylene (C₂H₂): CaC₂ (s)+ 2 H₂O (g)→ Ca(OH)₂ (s)+ C₂H₂ (g) Production of 3.3 g of C₂H₂ requires consumption of __________ g of H₂O.

There are __________ mol of carbon atoms in 3 mol of dimethylsulfoxide (C₂H₆SO).

Predict the product in the combination reaction below. Al (s)+ N₂ (g)→ __________

The combustion of propane (C₃H₈)produces CO₂ and H₂O: C₃H₈ (g)+ 5 O₂ (g)→ 3CO₂ (g)+ 4 H₂O (g) The reaction of 2.5 mol of O₂ with 4.6 mol of C₃H₈ will produce __________ mol of H₂O.

Sulfur and fluorine react in a combination reaction to produce sulfur hexafluoride: S (s)+ 3 F₃ (g)→ SF₆ (g) The maximum amount of SF₆ that can be produced from the reaction of 3.5 g of sulfur with 4.5 g of fluorine is __________ g.