Question 1

Which notation properly indicates how two molecules of diatomic oxygen would be represented in a chemical equation?

Accepted Answer

A) (O2)2 
B) O4 
C) 2O2 
D) O2O2 
E) All of the choices are correct. 
A) (O2)2 
B) O4 
C) 2O2 
D) O2O2 
E) All of the choices are correct.

Question 2

What is the mass of 3.01 mol of sulfur atoms?

Accepted Answer

A) 1.81 × 1024 g 
B) 32.06 g 
C) 3.01 g 
D) 0.150 g 
E) 96.5 g 
A) 1.81 × 1024 g 
B) 32.06 g 
C) 3.01 g 
D) 0.150 g 
E) 96.5 g

Question 3

Select the ionic compound that is insoluble in water.

Accepted Answer

A) Na2CO3 
B) Fe(NO3)3 
C) KBr 
D) MgS 
E) NH4Br 
A) Na2CO3 
B) Fe(NO3)3 
C) KBr 
D) MgS 
E) NH4Br

Question 4

A sample of sulfur contains 1.81 × 1024 atoms of sulfur.How many moles of sulfur does this represent?

Accepted Answer

A) 1.81 mol 
B) 3.01 mol 
C) 0.333 mol 
D) 1.09 mol 
E) 1.77 mol 
A) 1.81 mol 
B) 3.01 mol 
C) 0.333 mol 
D) 1.09 mol 
E) 1.77 mol

Question 5

Iron reacts with oxygen to form iron(III) oxide according to the chemical equation below.What is the theoretical yield of product when 5.00 grams of Fe react with excess O2? [Molar masses: Fe, 55.85 g/mol; O, 16.00g/mol] 4Fe(s) + 3O2(g) → 2Fe2O3(s)

Accepted Answer

A) 13.1 g 
B) 6.53 g 
C) 7.15 g 
D) 2.50 g 
E) 70.5 g 
A) 13.1 g 
B) 6.53 g 
C) 7.15 g 
D) 2.50 g 
E) 70.5 g

Question 6

Which symbol, often found in chemical equations, indicates that a substance is dissolved in water?

Accepted Answer

A) (w) 
B) (l) 
C) (aq) 
D) (d) 
E) (∆) 
A) (w) 
B) (l) 
C) (aq) 
D) (d) 
E) (∆)

Question 7

Consider the hypothetical reaction: 3A2 + 2B → C + 2D If 6.0 moles of A are mixed with 2.0 moles of B, what is the maximum amount of C that can be formed?

Accepted Answer

A) 1.0 mol 
B) 2.0 mol 
C) 5.0 mol 
D) 6.0 mol 
E) 8.0 mol 
A) 1.0 mol 
B) 2.0 mol 
C) 5.0 mol 
D) 6.0 mol 
E) 8.0 mol

Question 8

To convert a given number of moles into the number of atoms, one would multiply by which of the following factors?

Accepted Answer

A) 6.022 × 1023 atoms/1 mol 
B) 1 mol/6.022 × 1023 atoms 
C) 1.66 × 10-24 atoms/1 mol 
D) 1 mol/1.66 × 10-24 atoms 
E) molar mass 
A) 6.022 × 1023 atoms/1 mol 
B) 1 mol/6.022 × 1023 atoms 
C) 1.66 × 10-24 atoms/1 mol 
D) 1 mol/1.66 × 10-24 atoms 
E) molar mass

Question 9

One mole of iron contains 6.022 × 1023 grams of Fe.

Accepted Answer

A) True 
 B)False

Question 10

Classify the following reaction: Ce4+(aq) + Fe2+(aq) → Ce3+(aq) + Fe3+(aq)

Accepted Answer

A) precipitation 
B) acid - base 
C) oxidation - reduction 
D) decomposition 
E) combustion 
A) precipitation 
B) acid - base 
C) oxidation - reduction 
D) decomposition 
E) combustion

Question 11

Choose the best classification of the reaction represented by the following equation: Pb(NO3)2(aq) + CaCl2(aq) → PbCl2(s) + Ca(NO3)2(aq)

Accepted Answer

A) combustion 
B) acid-base 
C) decomposition 
D) precipitation 
E) oxidation-reduction 
A) combustion 
B) acid-base 
C) decomposition 
D) precipitation 
E) oxidation-reduction

Question 12

During an oxidation-reduction reaction, the oxidizing agent loses electrons.

Accepted Answer

A) True 
 B)False

Question 13

Dinitrogen monoxide, or laughing gas (N2O), is used as a dental anesthetic and as an aerosol propellant.How many molecules of N2O are present in a 12.6 g sample of the compound?

Accepted Answer

A) 1.72 × 1023 molecules 
B) 1.289 molecules 
C) 3.34 × 1026 molecules 
D) 7.59 × 1024 molecules 
E) 5.14 × 1023 molecules 
A) 1.72 × 1023 molecules 
B) 1.289 molecules 
C) 3.34 × 1026 molecules 
D) 7.59 × 1024 molecules 
E) 5.14 × 1023 molecules

Question 14

The chemical equation below is not balanced.What is the coefficient of iron when the equation is balanced with smallest whole number coefficients? Fe(s) + O2(g) → Fe2O3(s)

Accepted Answer

A) 1 
B) 2 
C) 3 
D) 4 
E) 8 
A) 1 
B) 2 
C) 3 
D) 4 
E) 8

Question 15

When solutions of sodium sulfide and copper(II) sulfate are mixed, a precipitate of copper(II) sulfide is formed.What is the net ionic equation for this reaction?

Accepted Answer

A) Na2S(aq) + CuSO4(aq) → Na2SO4(aq) + CuS(s) 
B) Na2S(aq) + CuSO4(aq) → CuS(s) 
C) Cu2+(aq) + S2-(aq) → Cu(s) + S(s) 
D) Cu2+(aq) + S2-(aq) → CuS(s) 
E) 2Na+(aq) + S2-(aq) + Cu2+(aq) + SO42-(aq) → 2Na+(aq) + SO42-(aq) 
A) Na2S(aq) + CuSO4(aq) → Na2SO4(aq) + CuS(s) 
B) Na2S(aq) + CuSO4(aq) → CuS(s) 
C) Cu2+(aq) + S2-(aq) → Cu(s) + S(s) 
D) Cu2+(aq) + S2-(aq) → CuS(s) 
E) 2Na+(aq) + S2-(aq) + Cu2+(aq) + SO42-(aq) → 2Na+(aq) + SO42-(aq)

Question 16

How is the reaction shown below best classified? Ca(s) + 2HCl(aq) → CaCl2(g) + H2(g)

Accepted Answer

A) decomposition 
B) combination 
C) single-replacement 
D) double-replacement 
E) precipitation 
A) decomposition 
B) combination 
C) single-replacement 
D) double-replacement 
E) precipitation

Question 17

Which of the choices is the correctly balanced form of the following equation? C6H14(l) + O2(g) → CO2(g) + H2O(l)

Accepted Answer

A) C6H14(l) + 13O2(g) → 6CO2(g) + 7H2O(l) 
B) C6H14(l) + 19O(g) → 6CO2(g) + 7H2O(l) 
C) C6H14(l) + 19O2(g) → 6CO2(g) + 7H2O(l) 
D) 2C6H14(l) + 19O2(g) → 12CO2(g) + 14H2O(l) 
E) C12H28(l) + 38O(g) → 12CO2(g) + 14H2O(l) 
A) C6H14(l) + 13O2(g) → 6CO2(g) + 7H2O(l) 
B) C6H14(l) + 19O(g) → 6CO2(g) + 7H2O(l) 
C) C6H14(l) + 19O2(g) → 6CO2(g) + 7H2O(l) 
D) 2C6H14(l) + 19O2(g) → 12CO2(g) + 14H2O(l) 
E) C12H28(l) + 38O(g) → 12CO2(g) + 14H2O(l)

Question 18

Choose the best classification of the reaction represented by the following equation: C6H12O6(s) + 6O2(g) → 6CO2(g) + 6H2O(l)

Accepted Answer

A) combustion 
B) acid-base 
C) precipitation 
D) decomposition 
E) combination 
A) combustion 
B) acid-base 
C) precipitation 
D) decomposition 
E) combination

Question 19

Choose the best classification of the reaction represented by the following equation: Na2SO4(aq) + Ba(OH)2(aq) → BaSO4(s) + 2NaOH(aq)

Accepted Answer

A) decomposition 
B) combination 
C) single-replacement 
D) double-replacement 
E) None of the choices are correct. 
A) decomposition 
B) combination 
C) single-replacement 
D) double-replacement 
E) None of the choices are correct.

Question 20

When the equation below is balanced with the lowest possible whole number coefficients, what is the sum of the coefficients? Ca(s) + HCl(g) → CaCl2(s) + H2(g)

Accepted Answer

A) 2 
B) 4 
C) 5 
D) 8 
E) 10 
A) 2 
B) 4 
C) 5 
D) 8 
E) 10

Exam 4: Calculations, Chemical Changes, and the Chemical Equation

Which notation properly indicates how two molecules of diatomic oxygen would be represented in a chemical equation?

What is the mass of 3.01 mol of sulfur atoms?

Select the ionic compound that is insoluble in water.

A sample of sulfur contains 1.81 × 1024 atoms of sulfur.How many moles of sulfur does this represent?

Iron reacts with oxygen to form iron(III) oxide according to the chemical equation below.What is the theoretical yield of product when 5.00 grams of Fe react with excess O2? [Molar masses: Fe, 55.85 g/mol; O, 16.00g/mol] 4Fe(s) + 3O2(g) → 2Fe2O3(s)

Which symbol, often found in chemical equations, indicates that a substance is dissolved in water?

Consider the hypothetical reaction: 3A2 + 2B → C + 2D If 6.0 moles of A are mixed with 2.0 moles of B, what is the maximum amount of C that can be formed?

To convert a given number of moles into the number of atoms, one would multiply by which of the following factors?

One mole of iron contains 6.022 × 1023 grams of Fe.

Classify the following reaction: Ce4+(aq) + Fe2+(aq) → Ce3+(aq) + Fe3+(aq)

Choose the best classification of the reaction represented by the following equation: Pb(NO3)2(aq) + CaCl2(aq) → PbCl2(s) + Ca(NO3)2(aq)

During an oxidation-reduction reaction, the oxidizing agent loses electrons.

Dinitrogen monoxide, or laughing gas (N2O), is used as a dental anesthetic and as an aerosol propellant.How many molecules of N2O are present in a 12.6 g sample of the compound?

The chemical equation below is not balanced.What is the coefficient of iron when the equation is balanced with smallest whole number coefficients? Fe(s) + O2(g) → Fe2O3(s)

When solutions of sodium sulfide and copper(II) sulfate are mixed, a precipitate of copper(II) sulfide is formed.What is the net ionic equation for this reaction?

How is the reaction shown below best classified? Ca(s) + 2HCl(aq) → CaCl2(g) + H2(g)

Which of the choices is the correctly balanced form of the following equation? C6H14(l) + O2(g) → CO2(g) + H2O(l)

Choose the best classification of the reaction represented by the following equation: C6H12O6(s) + 6O2(g) → 6CO2(g) + 6H2O(l)

Choose the best classification of the reaction represented by the following equation: Na2SO4(aq) + Ba(OH)2(aq) → BaSO4(s) + 2NaOH(aq)

When the equation below is balanced with the lowest possible whole number coefficients, what is the sum of the coefficients? Ca(s) + HCl(g) → CaCl2(s) + H2(g)

Chemistry:methods and Measurement

The Structure of the Atom and the Periodic Table

Structure and Properties of Ionic and Covalent Compounds

States of Matter- Gases, Liquids, and Solids

Solutions

Energy, Rate and Equilibrium

Acids and Bases

The Nucleus, Radioactivity, and Nuclear Medicine

An Introduction to Organic Chemistry- the Saturated Hydrocarbons

The Unsaturated Hydrocarbons- Alkenes, Alkynes, and Aromatics

Alcohols, Phenols, Thiols, and Ethers

Aldehydes and Ketones

Carboxylic Acids and Carboxylic Acid Derivatives

Amines and Amides

Carbohydrates

Lipids and Their Functions in Biochemical Systems

Protein Structure and Function

Enzymes

Introduction to Molecular Genetics

Carbohydrate Metabolism

Aerobic Respiration and Energy Production

Fatty Acid Metabolism

Filters

A sample of sulfur contains 1.81 × 10²⁴ atoms of sulfur.How many moles of sulfur does this represent?

Iron reacts with oxygen to form iron(III) oxide according to the chemical equation below.What is the theoretical yield of product when 5.00 grams of Fe react with excess O₂? [Molar masses: Fe, 55.85 g/mol; O, 16.00g/mol] 4Fe(s) + 3O₂(g) → 2Fe₂O₃(s)

Consider the hypothetical reaction: 3A₂ + 2B → C + 2D If 6.0 moles of A are mixed with 2.0 moles of B, what is the maximum amount of C that can be formed?

One mole of iron contains 6.022 × 10²³ grams of Fe.

Classify the following reaction: Ce⁴⁺(aq) + Fe²⁺(aq) → Ce³⁺(aq) + Fe³⁺(aq)

Choose the best classification of the reaction represented by the following equation: Pb(NO₃)₂(aq) + CaCl₂(aq) → PbCl₂(s) + Ca(NO₃)₂(aq)

Dinitrogen monoxide, or laughing gas (N₂O), is used as a dental anesthetic and as an aerosol propellant.How many molecules of N₂O are present in a 12.6 g sample of the compound?

The chemical equation below is not balanced.What is the coefficient of iron when the equation is balanced with smallest whole number coefficients? Fe(s) + O₂(g) → Fe₂O₃(s)

How is the reaction shown below best classified? Ca(s) + 2HCl(aq) → CaCl₂(g) + H₂(g)

Which of the choices is the correctly balanced form of the following equation? C₆H₁₄(l) + O₂(g) → CO₂(g) + H₂O(l)

Choose the best classification of the reaction represented by the following equation: C₆H₁₂O₆(s) + 6O₂(g) → 6CO₂(g) + 6H₂O(l)

Choose the best classification of the reaction represented by the following equation: Na₂SO₄(aq) + Ba(OH)₂(aq) → BaSO₄(s) + 2NaOH(aq)

When the equation below is balanced with the lowest possible whole number coefficients, what is the sum of the coefficients? Ca(s) + HCl(g) → CaCl₂(s) + H₂(g)