Question 1

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 2

Solid aluminum and gaseous oxygen react in a combination reaction to produce aluminum oxide: 4Al (s)+ 3O2 (g)→ 2Al2O3 (s)
In a particular experiment,the reaction of 2.5 g of Al with 2.5 g of O2 produced 3.5 g of Al2O3.The % yield of the reaction is ________.

Accepted Answer

A) 74 
B) 37 
C) 47 
D) 66 
E) 29 
A) 74 
B) 37 
C) 47 
D) 66 
E) 29

Question 3

How many grams of calcium cyanide (Ca(CN)2)are contained in 0.69 mol of calcium cyanide?

Accepted Answer

A) 64 
B) 0.0075 
C) 1.2 × 10-24 
D) 4.2 × 1023 
E) 92 
A) 64 
B) 0.0075 
C) 1.2 × 10-24 
D) 4.2 × 1023 
E) 92

Question 4

There are ________ sulfur atoms in 25 molecules of C4H4S2.

Accepted Answer

A) 1.5 × 1025 
B) 4.8 × 1025 
C) 3.0 × 1025 
D) 50 
E) 6.02 × 1023 
A) 1.5 × 1025 
B) 4.8 × 1025 
C) 3.0 × 1025 
D) 50 
E) 6.02 × 1023

Question 5

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

Accepted Answer

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

Question 6

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

Accepted Answer

A) C + O2 → CO2 
B) 2Mg + O2 → 2MgO 
C) 2N2 + 3H2 → 2NH3 
D) CaO + H2O → Ca(OH)2 
E) 2CH4 + 4O2 → 2CO2 + 4H2O 
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 the following equation is balanced,the coefficient of Al is ________. Al (s)+ H2O (l)→ Al(OH   (s)+ H2 (g)

Accepted Answer

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

Question 8

What is the empirical formula of a compound that contains 27.0% S,13.4% O,and 59.6% Cl by mass?

Accepted Answer

A) SOCl 
B) SOCl2 
C) S2OCl 
D) SO2Cl 
E) ClSO4 
A) SOCl 
B) SOCl2 
C) S2OCl 
D) SO2Cl 
E) ClSO4

Question 9

The combustion of propane (C3H8)in the presence of excess oxygen yields CO2 and H2O: C3H8 (g)+ 5O2 (g)→ 3CO2 (g)+ 4H2O (g)
When 2.5 mol of O2 are consumed in their reaction,________ mol of CO2 are produced.

Accepted Answer

A) 1.5 
B) 3.0 
C) 4.2 
D) 7.5 
E) 2.5 
A) 1.5 
B) 3.0 
C) 4.2 
D) 7.5 
E) 2.5

Question 10

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

Accepted Answer

A) 0.8452 
B) 1.183 
C) 6.022 × 1023 
D) 8.648 × 1023 
E) 3.134 × 1025 
A) 0.8452 
B) 1.183 
C) 6.022 × 1023 
D) 8.648 × 1023 
E) 3.134 × 1025

Question 11

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

Accepted Answer

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

Question 12

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

Accepted Answer

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

Question 13

Lithium and nitrogen react to produce lithium nitride: 6Li (s)+ N2 (g)→ 2Li3N (s)
How many moles of lithium nitride are produced when 0.330 mol of lithium react in this fashion?

Accepted Answer

A) 0.110 
B) 0.660 
C) 0.0550 
D) 0.990 
E) 0.165 
A) 0.110 
B) 0.660 
C) 0.0550 
D) 0.990 
E) 0.165

Question 14

A 1.36-g sample of magnesium nitrate,Mg(NO3)2,contains ________ mol of this compound.

Accepted Answer

A) 109 
B) 2.02 
C) 0.0157 
D) 0.0182 
E) 0.00917 
A) 109 
B) 2.02 
C) 0.0157 
D) 0.0182 
E) 0.00917

Question 15

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 16

How many moles of magnesium oxide are produced by the reaction of 1.82 g of magnesium nitride with   of water?
Mg3N2 + 3H2O → 2NH3 + 3MgO

Accepted Answer

A) 0.0180 
B) 0.0541 
C) 0.00601 
D) 0.984 
E) 3.00 
A) 0.0180 
B) 0.0541 
C) 0.00601 
D) 0.984 
E) 3.00

Question 17

What is the mass % of aluminum in aluminum sulfate (Al2(SO4)3)rounded to three significant figures?

Accepted Answer

A) 7.90 
B) 35.7 
C) 15.8 
D) 19.4 
E) 342.2 
A) 7.90 
B) 35.7 
C) 15.8 
D) 19.4 
E) 342.2

Question 18

Automotive air bags inflate when sodium azide decomposes explosively to its constituent elements: 2NaN3 (s)→ 2Na (s)+ 3N2 (g)
How many grams of sodium azide are required to produce 28.0 g of nitrogen?

Accepted Answer

A) 1.50 
B) 0.666 
C) 65.0 
D) 43.3 
E) 97.5 
A) 1.50 
B) 0.666 
C) 65.0 
D) 43.3 
E) 97.5

Question 19

The molecular weight of ethanol (C2H5OH),rounded to one decimal place,is ________ amu.

Accepted Answer

A) 45.1 
B) 34.1 
C) 29.1 
D) 46.1 
E) 29.0 
A) 45.1 
B) 34.1 
C) 29.1 
D) 46.1 
E) 29.0

Question 20

The molecular weight of maltose ( C12H22O11 ),rounded to one decimal place,is ________ amu.

Accepted Answer

A) 507.2 
B) 182.0 
C) 45.0 
D) 342.3 
E) 29.0 
A) 507.2 
B) 182.0 
C) 45.0 
D) 342.3 
E) 29.0

Exam 3: Chemical Reactions and Reaction Stoichiometry

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

Solid aluminum and gaseous oxygen react in a combination reaction to produce aluminum oxide: 4Al (s)+ 3O2 (g)→ 2Al2O3 (s) In a particular experiment,the reaction of 2.5 g of Al with 2.5 g of O2 produced 3.5 g of Al2O3.The % yield of the reaction is ________.

How many grams of calcium cyanide (Ca(CN)2)are contained in 0.69 mol of calcium cyanide?

There are ________ sulfur atoms in 25 molecules of C4H4S2.

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

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

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

What is the empirical formula of a compound that contains 27.0% S,13.4% O,and 59.6% Cl by mass?

The combustion of propane (C3H8)in the presence of excess oxygen yields CO2 and H2O: C3H8 (g)+ 5O2 (g)→ 3CO2 (g)+ 4H2O (g) When 2.5 mol of O2 are consumed in their reaction,________ mol of CO2 are produced.

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

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

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

Lithium and nitrogen react to produce lithium nitride: 6Li (s)+ N2 (g)→ 2Li3N (s) How many moles of lithium nitride are produced when 0.330 mol of lithium react in this fashion?

A 1.36-g sample of magnesium nitrate,Mg(NO3)2,contains ________ mol of this compound.

The reaction used to inflate automobile airbags ________.

How many moles of magnesium oxide are produced by the reaction of 1.82 g of magnesium nitride with of water? Mg3N2 + 3H2O → 2NH3 + 3MgO

What is the mass % of aluminum in aluminum sulfate (Al2(SO4)3)rounded to three significant figures?

Automotive air bags inflate when sodium azide decomposes explosively to its constituent elements: 2NaN3 (s)→ 2Na (s)+ 3N2 (g) How many grams of sodium azide are required to produce 28.0 g of nitrogen?

The molecular weight of ethanol (C2H5OH),rounded to one decimal place,is ________ amu.

The molecular weight of maltose ( C12H22O11 ),rounded to one decimal place,is ________ amu.

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

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

Solid aluminum and gaseous oxygen react in a combination reaction to produce aluminum oxide: 4Al (s)+ 3O₂ (g)→ 2Al₂O₃(s) In a particular experiment,the reaction of 2.5 g of Al with 2.5 g of O₂ produced 3.5 g of Al₂O₃.The % yield of the reaction is ________.

How many grams of calcium cyanide (Ca(CN)₂)are contained in 0.69 mol of calcium cyanide?

There are ________ sulfur atoms in 25 molecules of C₄H₄S₂.

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

The combustion of propane (C₃H₈)in the presence of excess oxygen yields CO₂and H₂O: C₃H₈ (g)+ 5O₂(g)→ 3CO₂ (g)+ 4H₂O (g) When 2.5 mol of O₂are consumed in their reaction,________ mol of CO₂ are produced.

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

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

Lithium and nitrogen react to produce lithium nitride: 6Li (s)+ N₂(g)→ 2Li₃N (s) How many moles of lithium nitride are produced when 0.330 mol of lithium react in this fashion?

A 1.36-g sample of magnesium nitrate,Mg(NO₃)₂,contains ________ mol of this compound.

How many moles of magnesium oxide are produced by the reaction of 1.82 g of magnesium nitride with of water? Mg₃N₂ + 3H₂O → 2NH₃ + 3MgO

What is the mass % of aluminum in aluminum sulfate (Al₂(SO₄)₃)rounded to three significant figures?

Automotive air bags inflate when sodium azide decomposes explosively to its constituent elements: 2NaN₃ (s)→ 2Na (s)+ 3N₂ (g) How many grams of sodium azide are required to produce 28.0 g of nitrogen?

The molecular weight of ethanol (C₂H₅OH),rounded to one decimal place,is ________ amu.

The molecular weight of maltose ( C₁₂H₂₂O₁₁ ),rounded to one decimal place,is ________ amu.