Question 1

What is the change in the oxidation number of nitrogen in the following? HNO₃ $\rarr$ NO

Accepted Answer

In HNO3, the oxidation number of nitrogen is +5. In NO, the oxidation number of nitrogen is +2. Therefore, the oxidation number decreases by 3 units.

Question 2

What is the change in the oxidation number of manganese in the following? KMnO₄ $\rarr$ MnSO₄

Accepted Answer

In KMnO4, manganese has an oxidation number of +7. In MnSO4, manganese has an oxidation number of +2. The change in oxidation number is a decrease of 5 units, from +7 to +2.

Question 3

What is the change in the oxidation number of sulfur in the following? K₂SO₃ $\rarr$ K₂SO₄

Accepted Answer

In K2SO3, sulfur has an oxidation state of +4. In K2SO4, sulfur has an oxidation state of +6. Therefore, the oxidation number of sulfur increases by 2 units.

Question 4

What is the change in the oxidation number of iodine in the following? KI $\rarr$ KIO₃

Accepted Answer

The answer of What is the change in the oxidation...

Question 5

What is the change in the oxidation number of carbon in the following? K₂C₂O₄ $\rarr$ K₂CO₃

Accepted Answer

The answer of What is the change in the oxidation...

Question 6

In the equation, C₄H₁₀(l)+ Cr₂O₇^2-(aq)+ H⁺(aq)$\rarr$ H₆C₄O₄(s)+ Cr³⁺(aq)+ H₂O(l), the change in the oxidation number of the chromium atom is

Accepted Answer

The oxidation state of chromium in Cr₂O₇²⁻ is +6, and it changes to +3 in Cr³⁺, indicating a decrease by three units.

Question 7

In the equation, CrO₄^2-(aq)+ H₂O(l)$\rarr$ CrO₂^-(aq)+ OH^-(aq), the change in the oxidation number of the chromium atom is

Accepted Answer

The oxidation state of chromium in CrO₄²⁻ is +6, and in CrO₂⁻ it is +3. Thus, the oxidation number decreases by three units.

Question 8

The sulfite ion (SO₃^2-)was involved in a chemical reaction in which it underwent oxidation. Based on the change in oxidation numbers, which of the species listed below is a possible oxidation product of the reaction?

Accepted Answer

The oxidation state of sulfur in SO₃²⁻ is +4. In SO₄²⁻, the oxidation state of sulfur is +6, indicating an increase in oxidation state, which is characteristic of oxidation.

Question 9

The nitrogen molecule, (N₂), was involved in a chemical reaction in which it underwent reduction. Based on the change in oxidation numbers, which of the species listed below is a possible product of the reaction?

Accepted Answer

In N2, nitrogen has an oxidation state of 0. In N2H4, nitrogen is reduced to an oxidation state of -2, indicating a gain of electrons.

Question 10

The ClO₂ molecule was involved in a chemical reaction in which it underwent oxidation. Based on the change in oxidation numbers, which of the species listed below is a possible product of the reaction?

Accepted Answer

The answer of The ClO₂ molecule was involved in a...

Question 11

The NO molecule underwent oxidation during a chemical reaction. Which one of the species listed below is a possible product of the reaction?

Accepted Answer

NO can be oxidized to form NO2 or NO2- (nitrite ion) as it gains oxygen or loses electrons.

Question 12

The following unbalanced equation describes the production of metallic iron: Fe₂O₃ + C $\rarr$ Fe + CO₂ What is the change in oxidation number for the carbon atom?

Accepted Answer

The answer of The following unbalanced equation describes the production...

Question 13

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

Accepted Answer

In both SiO2 and CaSiO3, the oxidation state of silicon is +4. Therefore, there is no change in the oxidation number of the silicon atom.

Question 14

Consider the redox equation below: C₄H₁₀(g)+ Cr₂O₇²(aq)+ H⁺(aq)$\rarr$ H₆C₄O₄(aq)+ Cr³⁺(aq)+ H₂O(l)The reducing agent is

Accepted Answer

C₄H₁₀(g) is oxidized to H₆C₄O₄(aq), so it is the reducing agent.

Question 15

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

Accepted Answer

Cr₂O₇^2- is the oxidizing agent because it is reduced (gains electrons) in the reaction.

Question 16

Consider the unbalanced redox equation, VO₄^3-(aq)+ SO₂(g)+ 2 H⁺(aq)$\rarr$ VO²⁺(aq)+ SO₄^2-(aq)+ H₂O(l)The reducing agent is

Accepted Answer

SO₂ is the reducing agent because it donates electrons and gets oxidized to SO₄²⁻.

Question 17

Consider the redox equation, 2VO₄^3-(aq)+ SO₂(g)+ 8H⁺(aq)$\rarr$ 2VO²⁺(aq)+ SO₄^2-(aq)+ 4H₂O(l) The oxidizing agent is

Accepted Answer

The answer of Consider the redox equation, 2VO₄^3-(aq)+ SO₂(g)+ 8H⁺(aq)$\rarr$...

Question 18

Consider the redox equation, 2VO₄^3-(aq)+ SO₂(g)+ 8H⁺(aq)$\rarr$2VO²⁺(aq)+ SO₄^2-(aq)+ 4H₂O(l) Which of the following is correct?Hint: Write out the oxidation numbers for each element in the equation then compare.

Accepted Answer

The oxidation number of vanadium (V) in VO₄³⁻ decreases from +5 to +4 in VO²⁺, indicating it gains an electron and acts as an oxidizing agent.

Question 19

The following unbalanced equation describes the production of metallic iron: Fe₂O₃ + C $\rarr$ Fe + CO₂ Which is true?Hint: Remember the reducing agent is oxidized and the oxidizing agent is reduced.

Accepted Answer

Fe2O3 is the oxidizing agent because it gains electrons (is reduced) to form Fe, while C is the reducing agent because it loses electrons (is oxidized) to form CO2.

Question 20

Balance the half-reaction, H₂S $\rarr$ S₈, 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

The answer of Balance the half-reaction, H₂S $\rarr$ S₈, taking...

Quiz 6: Oxidation-Reduction Reactions

What is the change in the oxidation number of nitrogen in the following? HNO₃ $\rarr$ NO

What is the change in the oxidation number of manganese in the following? KMnO₄ $\rarr$ MnSO₄

What is the change in the oxidation number of sulfur in the following? K₂SO₃ $\rarr$ K₂SO₄

What is the change in the oxidation number of iodine in the following? KI $\rarr$ KIO₃

What is the change in the oxidation number of carbon in the following? K₂C₂O₄ $\rarr$ K₂CO₃

In the equation, C₄H₁₀(l) + Cr₂O₇^2-(aq) + H⁺(aq) $\rarr$ H₆C₄O₄(s) + Cr³⁺(aq) + H₂O(l) , the change in the oxidation number of the chromium atom is

In the equation, CrO₄^2-(aq) + H₂O(l) $\rarr$ CrO₂^-(aq) + OH^-(aq) , the change in the oxidation number of the chromium atom is

The sulfite ion (SO₃^2-) was involved in a chemical reaction in which it underwent oxidation. Based on the change in oxidation numbers, which of the species listed below is a possible oxidation product of the reaction?

The nitrogen molecule, (N₂) , was involved in a chemical reaction in which it underwent reduction. Based on the change in oxidation numbers, which of the species listed below is a possible product of the reaction?

The ClO₂ molecule was involved in a chemical reaction in which it underwent oxidation. Based on the change in oxidation numbers, which of the species listed below is a possible product of the reaction?

The NO molecule underwent oxidation during a chemical reaction. Which one of the species listed below is a possible product of the reaction?

The following unbalanced equation describes the production of metallic iron: Fe₂O₃ + C $\rarr$ Fe + CO₂ What is the change in oxidation number for the carbon atom?

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

Consider the redox equation below: C₄H₁₀(g) + Cr₂O₇²(aq) + H⁺(aq) $\rarr$ H₆C₄O₄(aq) + Cr³⁺(aq) + H₂O(l) The reducing agent is

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

Consider the unbalanced redox equation, VO₄^3-(aq) + SO₂(g) + 2 H⁺(aq) $\rarr$ VO²⁺(aq) + SO₄^2-(aq) + H₂O(l) The reducing agent is

Consider the redox equation, 2VO₄^3-(aq) + SO₂(g) + 8H⁺(aq) $\rarr$ 2VO²⁺(aq) + SO₄^2-(aq) + 4H₂O(l) The oxidizing agent is

Consider the redox equation, 2VO₄^3-(aq) + SO₂(g) + 8H⁺(aq) $\rarr$ 2VO²⁺(aq) + SO₄^2-(aq) + 4H₂O(l) Which of the following is correct?Hint: Write out the oxidation numbers for each element in the equation then compare.

The following unbalanced equation describes the production of metallic iron: Fe₂O₃ + C $\rarr$ Fe + CO₂ Which is true?Hint: Remember the reducing agent is oxidized and the oxidizing agent is reduced.

Balance the half-reaction, H₂S $\rarr$ S₈, 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.

Quiz 6: Oxidation-Reduction Reactions

What is the change in the oxidation number of nitrogen in the following? HNO3 →\rarr→ NO

What is the change in the oxidation number of manganese in the following? KMnO4 →\rarr→ MnSO4

What is the change in the oxidation number of sulfur in the following? K2SO3 →\rarr→ K2SO4

What is the change in the oxidation number of iodine in the following? KI →\rarr→ KIO3

What is the change in the oxidation number of carbon in the following? K2C2O4 →\rarr→ K2CO3

In the equation, C4H10(l) + Cr2O72-(aq) + H+(aq) →\rarr→ H6C4O4(s) + Cr3+(aq) + H2O(l) , the change in the oxidation number of the chromium atom is

In the equation, CrO42-(aq) + H2O(l) →\rarr→ CrO2-(aq) + OH-(aq) , the change in the oxidation number of the chromium atom is

The sulfite ion (SO32-) was involved in a chemical reaction in which it underwent oxidation. Based on the change in oxidation numbers, which of the species listed below is a possible oxidation product of the reaction?

The nitrogen molecule, (N2) , was involved in a chemical reaction in which it underwent reduction. Based on the change in oxidation numbers, which of the species listed below is a possible product of the reaction?

The ClO2 molecule was involved in a chemical reaction in which it underwent oxidation. Based on the change in oxidation numbers, which of the species listed below is a possible product of the reaction?

The NO molecule underwent oxidation during a chemical reaction. Which one of the species listed below is a possible product of the reaction?

The following unbalanced equation describes the production of metallic iron: Fe2O3 + C →\rarr→ Fe + CO2 What is the change in oxidation number for the carbon atom?

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

Consider the redox equation below: C4H10(g) + Cr2O72(aq) + H+(aq) →\rarr→ H6C4O4(aq) + Cr3+(aq) + H2O(l) The reducing agent is

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

Consider the unbalanced redox equation, VO43-(aq) + SO2(g) + 2 H+(aq) →\rarr→ VO2+(aq) + SO42-(aq) + H2O(l) The reducing agent is

Consider the redox equation, 2VO43-(aq) + SO2(g) + 8H+(aq) →\rarr→ 2VO2+(aq) + SO42-(aq) + 4H2O(l) The oxidizing agent is

Consider the redox equation, 2VO43-(aq) + SO2(g) + 8H+(aq) →\rarr→ 2VO2+(aq) + SO42-(aq) + 4H2O(l) Which of the following is correct?Hint: Write out the oxidation numbers for each element in the equation then compare.

The following unbalanced equation describes the production of metallic iron: Fe2O3 + C →\rarr→ Fe + CO2 Which is true?Hint: Remember the reducing agent is oxidized and the oxidizing agent is reduced.

Balance the half-reaction, H2S →\rarr→ S8, 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.

What is the change in the oxidation number of nitrogen in the following? HNO₃ $\rarr$ NO

What is the change in the oxidation number of manganese in the following? KMnO₄ $\rarr$ MnSO₄

What is the change in the oxidation number of sulfur in the following? K₂SO₃ $\rarr$ K₂SO₄

What is the change in the oxidation number of iodine in the following? KI $\rarr$ KIO₃

What is the change in the oxidation number of carbon in the following? K₂C₂O₄ $\rarr$ K₂CO₃

In the equation, C₄H₁₀(l) + Cr₂O₇^2-(aq) + H⁺(aq) $\rarr$ H₆C₄O₄(s) + Cr³⁺(aq) + H₂O(l) , the change in the oxidation number of the chromium atom is

In the equation, CrO₄^2-(aq) + H₂O(l) $\rarr$ CrO₂^-(aq) + OH^-(aq) , the change in the oxidation number of the chromium atom is

The sulfite ion (SO₃^2-) was involved in a chemical reaction in which it underwent oxidation. Based on the change in oxidation numbers, which of the species listed below is a possible oxidation product of the reaction?

The nitrogen molecule, (N₂) , was involved in a chemical reaction in which it underwent reduction. Based on the change in oxidation numbers, which of the species listed below is a possible product of the reaction?

The ClO₂ molecule was involved in a chemical reaction in which it underwent oxidation. Based on the change in oxidation numbers, which of the species listed below is a possible product of the reaction?

The following unbalanced equation describes the production of metallic iron: Fe₂O₃ + C $\rarr$ Fe + CO₂ What is the change in oxidation number for the carbon atom?

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

Consider the redox equation below: C₄H₁₀(g) + Cr₂O₇²(aq) + H⁺(aq) $\rarr$ H₆C₄O₄(aq) + Cr³⁺(aq) + H₂O(l) The reducing agent is

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

Consider the unbalanced redox equation, VO₄^3-(aq) + SO₂(g) + 2 H⁺(aq) $\rarr$ VO²⁺(aq) + SO₄^2-(aq) + H₂O(l) The reducing agent is

Consider the redox equation, 2VO₄^3-(aq) + SO₂(g) + 8H⁺(aq) $\rarr$ 2VO²⁺(aq) + SO₄^2-(aq) + 4H₂O(l) The oxidizing agent is

Consider the redox equation, 2VO₄^3-(aq) + SO₂(g) + 8H⁺(aq) $\rarr$ 2VO²⁺(aq) + SO₄^2-(aq) + 4H₂O(l) Which of the following is correct?Hint: Write out the oxidation numbers for each element in the equation then compare.

The following unbalanced equation describes the production of metallic iron: Fe₂O₃ + C $\rarr$ Fe + CO₂ Which is true?Hint: Remember the reducing agent is oxidized and the oxidizing agent is reduced.

Balance the half-reaction, H₂S $\rarr$ S₈, 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.