Question 1

What is the change in the oxidation number of carbon in the following? 
CO $\rarr$ CO2

Accepted Answer

A) increase by two units 
B) increase by three units 
C) increase by four units 
D) decrease by three units 
E) decrease by four units 
A) increase by two units 
B) increase by three units 
C) increase by four units 
D) decrease by three units 
E) decrease by four units

Question 2

An oxidation reaction involves the loss of electrons.

Accepted Answer

A) True 
 B)False

Question 3

The oxidation number of Mn in Mn2O7 is ________.

Accepted Answer

Question 4

When the equation, Al(s)+ NO3-(aq)→ NO(g)+ Al3+(aq)is balanced for an acidic solution, the Al/NO3- ratio is ________. Hint: H+ are present in an acidic solution.

Accepted Answer

Question 5

Zinc metal reacts with nitric acid solution to produce zinc nitrate (in solution), ammonium nitrate (in solution), and water. The species being reduced in this reaction is

Accepted Answer

A) HNO3(aq). 
B) NH4+(aq). 
C) Zn2+(aq). 
D) Zn(s). 
E) Zn(NO3)2(aq). 
A) HNO3(aq). 
B) NH4+(aq). 
C) Zn2+(aq). 
D) Zn(s). 
E) Zn(NO3)2(aq).

Question 6

What is the oxidation number of nitrogen in (NH4)2SO4?

Accepted Answer

A) -3 
B) -2 
C) +1 
D) +2 
E) +3 
A) -3 
B) -2 
C) +1 
D) +2 
E) +3

Question 7

What is the oxidation number of cobalt in Co2(SO4)3?

Accepted Answer

A) +3 
B) +6 
C) +9 
D) +15 
E) +30 
A) +3 
B) +6 
C) +9 
D) +15 
E) +30

Question 8

Balance the half-reaction, NO3 $\rarr$ NH4+, taking place in acidic media. How many electrons are needed to balance the half-reaction?Hint: Remember the coefficients when balancing half-reactions and look carefully at the oxidation numbers.

Accepted Answer

A) 2 electrons, left side 
B) 3 electrons, right side 
C) 4 electrons, left side 
D) 8 electrons, left side 
E) 8 electrons, right side 
A) 2 electrons, left side 
B) 3 electrons, right side 
C) 4 electrons, left side 
D) 8 electrons, left side 
E) 8 electrons, right side

Question 9

Sodium bicarbonate, (NaHCO3), in solution reacts with hydrochloric acid solution to produce aqueous sodium chloride, carbon dioxide gas, and water. The species being reduced in this reaction is Hint: Oxidation is a loss of electrons and reduction is a gain of electrons.

Accepted Answer

A) HCO3- (aq). 
B) CO2(g). 
C) HCl(aq). 
D) Cl-(aq). 
E) none of the above. 
A) HCO3- (aq). 
B) CO2(g). 
C) HCl(aq). 
D) Cl-(aq). 
E) none of the above.

Question 10

What is the compound formed in the reaction between hydrogen sulfide and silver metal, which is responsible for the dull film on the silver metal when it tarnishes in air?

Accepted Answer

A) Ag2SO4 
B) AgHSO4 
C) Ag2S 
D) Ag2CO3 
E) Ag2SO3 
A) Ag2SO4 
B) AgHSO4 
C) Ag2S 
D) Ag2CO3 
E) Ag2SO3

Question 11

Consider the unbalanced redox equation , C4H10(l)+ Cr2O72-(aq) + H+(aq)$\rarr$ H6C4O4(s)+ Cr3+(aq)+ H2O(l)The oxidizing agent is

Accepted Answer

A) C4H10(l) 
B) Cr2O72-(aq) 
C) H+(aq) 
D) H6C4O4(s) 
E) Cr3+(aq) 
A) C4H10(l) 
B) Cr2O72-(aq) 
C) H+(aq) 
D) H6C4O4(s) 
E) Cr3+(aq)

Question 12

Balance the half-reaction, Cl2O7 $\rarr$ HClO, taking place in acidic media. How many electrons are needed to balance the half-reaction?Hint: Remember the coefficients when balancing half-reactions and look carefully at the oxidation numbers.

Accepted Answer

A) 2 electrons, left side 
B) 3 electrons, right side 
C) 12 electrons, left side 
D) 6 electrons, right side 
E) 8 electrons, left side 
A) 2 electrons, left side 
B) 3 electrons, right side 
C) 12 electrons, left side 
D) 6 electrons, right side 
E) 8 electrons, left side

Question 13

Rust is a hydrated compound formed between iron and oxygen, in the presence of water. The formula is approximately Fe2O3•32H2O. What is the oxidation number of the iron ion?

Accepted Answer

Question 14

Given the following chemical equation: SiO2 + CaCO3 $\rarr$CaSiO3 + CO2 What is the change in oxidation number for silicon atom?

Accepted Answer

A) There is no change. 
B) decreases by 1 
C) increases by 2 
D) decreases by 3 
E) increases by 4 
A) There is no change. 
B) decreases by 1 
C) increases by 2 
D) decreases by 3 
E) increases by 4

Question 15

What is the equation that best describes the oxidation of iron by oxygen in the presence of moisture? Hint: Be sure to consider the oxidation numbers when determining the equation.

Accepted Answer

A) Fe2+(aq)+ H2O(aq)+ O2(g)$\rarr$ FeO(s)+ H2(g)+ O2(g) 
B) 4 H+(aq)+ 2Fe(s)+ O2(g)$\rarr$ 2H2O(l)+ 2Fe2+ (aq) 
C) 4Fe(s)+ 3O2(g)+ 2xH2O $\rarr$ 2Fe2O3·xH2O(s) 
D) Fe(s)+ 2H2O(aq)+ O2(g)$\rarr$ Fe(OH)2(s)+ H2O2(l) 
E) 2Fe(s)+ 6H2O(aq)+ O2(g)$\rarr$ 2Fe(OH)3(s)+ 3H2(g)+ O2(g) 
A) Fe2+(aq)+ H2O(aq)+ O2(g)$\rarr$ FeO(s)+ H2(g)+ O2(g) 
B) 4 H+(aq)+ 2Fe(s)+ O2(g)$\rarr$ 2H2O(l)+ 2Fe2+ (aq) 
C) 4Fe(s)+ 3O2(g)+ 2xH2O $\rarr$ 2Fe2O3·xH2O(s) 
D) Fe(s)+ 2H2O(aq)+ O2(g)$\rarr$ Fe(OH)2(s)+ H2O2(l) 
E) 2Fe(s)+ 6H2O(aq)+ O2(g)$\rarr$ 2Fe(OH)3(s)+ 3H2(g)+ O2(g)

What is the change in the oxidation number of carbon in the following? CO $\rarr$ CO₂

An oxidation reaction involves the loss of electrons.

The oxidation number of Mn in Mn₂O₇ is ________.

When the equation, Al(s)+ NO₃^-(aq)→ NO(g)+ Al³⁺(aq)is balanced for an acidic solution, the Al/NO₃^- ratio is ________. Hint: H⁺^{are present in an acidic solution.}

Zinc metal reacts with nitric acid solution to produce zinc nitrate (in solution), ammonium nitrate (in solution), and water. The species being reduced in this reaction is

What is the oxidation number of nitrogen in (NH₄)₂SO₄?

What is the oxidation number of cobalt in Co₂(SO₄)₃?

Balance the half-reaction, NO₃ $\rarr$ NH₄⁺, taking place in acidic media. How many electrons are needed to balance the half-reaction?Hint: Remember the coefficients when balancing half-reactions and look carefully at the oxidation numbers.

Sodium bicarbonate, (NaHCO₃), in solution reacts with hydrochloric acid solution to produce aqueous sodium chloride, carbon dioxide gas, and water. The species being reduced in this reaction is Hint: Oxidation is a loss of electrons and reduction is a gain of electrons.

What is the compound formed in the reaction between hydrogen sulfide and silver metal, which is responsible for the dull film on the silver metal when it tarnishes in air?

Consider the unbalanced redox equation , C₄H₁₀(l)+ Cr₂O₇^2-(aq)+ H⁺(aq) $\rarr$ H₆C₄O₄(s)+ Cr³⁺(aq)+ H₂O(l)The oxidizing agent is

Balance the half-reaction, Cl₂O₇ $\rarr$ HClO, taking place in acidic media. How many electrons are needed to balance the half-reaction?Hint: Remember the coefficients when balancing half-reactions and look carefully at the oxidation numbers.

Rust is a hydrated compound formed between iron and oxygen, in the presence of water. The formula is approximately Fe₂O₃•32H₂O. What is the oxidation number of the iron ion?

Given the following chemical equation: SiO₂ + CaCO₃ $\rarr$ CaSiO₃ + CO₂ What is the change in oxidation number for silicon atom?

What is the equation that best describes the oxidation of iron by oxygen in the presence of moisture? Hint: Be sure to consider the oxidation numbers when determining the equation.

A Very Brief History of Chemistry

Scientific Measurements

Elements, Compounds, and the Periodic Table

The Mole and Stoichiometry

Molecular View of Reactions in Aqueous Solutions

Energy and Chemical Change

The Quantum Mechanical Atom

The Basics of Chemical Bonding

Theories of Bonding and Structure

Properties of Gases

Intermolecular Attractions and the Properties of Liquids and Solids

Mixtures at the Molecular Level: Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Acids and Bases, a Molecular Look

Acid-Base Equilibria in Aqueous Solutions

Solubility and Simultaneous Equilibria

Thermodynamics

Electrochemistry

Nuclear Reactions and Their Role in Chemistry

Metal Complexes

Organic Compounds, Polymers, and Biochemicals

Filters

Exam 6: Oxidation-Reduction Reactions

What is the change in the oxidation number of carbon in the following? CO →\rarr→ CO2

An oxidation reaction involves the loss of electrons.

The oxidation number of Mn in Mn2O7 is ________.

When the equation, Al(s)+ NO3-(aq)→ NO(g)+ Al3+(aq)is balanced for an acidic solution, the Al/NO3- ratio is ________. Hint: H+ are present in an acidic solution.

Zinc metal reacts with nitric acid solution to produce zinc nitrate (in solution), ammonium nitrate (in solution), and water. The species being reduced in this reaction is

What is the oxidation number of nitrogen in (NH4)2SO4?

What is the oxidation number of cobalt in Co2(SO4)3?

Balance the half-reaction, NO3 →\rarr→ NH4+, taking place in acidic media. How many electrons are needed to balance the half-reaction?Hint: Remember the coefficients when balancing half-reactions and look carefully at the oxidation numbers.

Sodium bicarbonate, (NaHCO3), in solution reacts with hydrochloric acid solution to produce aqueous sodium chloride, carbon dioxide gas, and water. The species being reduced in this reaction is Hint: Oxidation is a loss of electrons and reduction is a gain of electrons.

What is the compound formed in the reaction between hydrogen sulfide and silver metal, which is responsible for the dull film on the silver metal when it tarnishes in air?

Consider the unbalanced redox equation , C4H10(l)+ Cr2O72-(aq) + H+(aq) →\rarr→ H6C4O4(s)+ Cr3+(aq)+ H2O(l)The oxidizing agent is

Balance the half-reaction, Cl2O7 →\rarr→ HClO, taking place in acidic media. How many electrons are needed to balance the half-reaction?Hint: Remember the coefficients when balancing half-reactions and look carefully at the oxidation numbers.

Rust is a hydrated compound formed between iron and oxygen, in the presence of water. The formula is approximately Fe2O3•32H2O. What is the oxidation number of the iron ion?

Given the following chemical equation: SiO2 + CaCO3 →\rarr→ CaSiO3 + CO2 What is the change in oxidation number for silicon atom?

What is the equation that best describes the oxidation of iron by oxygen in the presence of moisture? Hint: Be sure to consider the oxidation numbers when determining the equation.

A Very Brief History of Chemistry

Scientific Measurements

Elements, Compounds, and the Periodic Table

The Mole and Stoichiometry

Molecular View of Reactions in Aqueous Solutions

Energy and Chemical Change

The Quantum Mechanical Atom

The Basics of Chemical Bonding

Theories of Bonding and Structure

Properties of Gases

Intermolecular Attractions and the Properties of Liquids and Solids

Mixtures at the Molecular Level: Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Acids and Bases, a Molecular Look

Acid-Base Equilibria in Aqueous Solutions

Solubility and Simultaneous Equilibria

Thermodynamics

Electrochemistry

Nuclear Reactions and Their Role in Chemistry

Metal Complexes

Organic Compounds, Polymers, and Biochemicals

Filters

What is the change in the oxidation number of carbon in the following? CO $\rarr$ CO₂

The oxidation number of Mn in Mn₂O₇ is ________.

When the equation, Al(s)+ NO₃^-(aq)→ NO(g)+ Al³⁺(aq)is balanced for an acidic solution, the Al/NO₃^- ratio is ________. Hint: H⁺^{are present in an acidic solution.}

What is the oxidation number of nitrogen in (NH₄)₂SO₄?

What is the oxidation number of cobalt in Co₂(SO₄)₃?

Balance the half-reaction, NO₃ $\rarr$ NH₄⁺, taking place in acidic media. How many electrons are needed to balance the half-reaction?Hint: Remember the coefficients when balancing half-reactions and look carefully at the oxidation numbers.

Sodium bicarbonate, (NaHCO₃), in solution reacts with hydrochloric acid solution to produce aqueous sodium chloride, carbon dioxide gas, and water. The species being reduced in this reaction is Hint: Oxidation is a loss of electrons and reduction is a gain of electrons.

Consider the unbalanced redox equation , C₄H₁₀(l)+ Cr₂O₇^2-(aq)+ H⁺(aq) $\rarr$ H₆C₄O₄(s)+ Cr³⁺(aq)+ H₂O(l)The oxidizing agent is

Balance the half-reaction, Cl₂O₇ $\rarr$ HClO, taking place in acidic media. How many electrons are needed to balance the half-reaction?Hint: Remember the coefficients when balancing half-reactions and look carefully at the oxidation numbers.

Rust is a hydrated compound formed between iron and oxygen, in the presence of water. The formula is approximately Fe₂O₃•32H₂O. What is the oxidation number of the iron ion?

Given the following chemical equation: SiO₂ + CaCO₃ $\rarr$ CaSiO₃ + CO₂ What is the change in oxidation number for silicon atom?