Question 1

Balance the following redox reaction if it occurs in H₂SO₄.What are the coefficients in front of H₂O and Cr₂(SO₄)₃ in the balanced reaction? C₃H₈O₂(aq)+ K₂Cr₂O₇(aq)→ C₃H₄O₄(aq)+ Cr₂(SO₄)₃(aq)

Accepted Answer

D

Question 2

Balance the following reaction in KOH.What are the coefficients in front of C₃H₈O₂ and KMnO₄ in the balanced reaction? C₃H₈O₂(aq)+ KMnO₄(aq)→ C₃H₂O₄K₂(aq)+ MnO₂(aq)

Accepted Answer

A

Question 3

What element is being oxidized in the following redox reaction? C₃H₈O₂(aq)+ KMnO₄(aq)→ C₃H₂O₄K₂(aq)+ MnO₂(aq)

Accepted Answer

Carbon is being oxidized as it goes from a lower oxidation state in C3H8O2 to a higher oxidation state in C3H2O4K2.

Question 4

Balance the following redox reaction if it occurs in basic solution.What are the coefficients in front of Br₂and OH⁻ in the balanced reaction? Br₂(l)→ BrO₃⁻(aq)+ Br⁻(aq)

Accepted Answer

1. Assign oxidation states to each element: 
BrS1U1B12S1U1B0(l) → BrOS1U1B13S1U1B0⁻(aq) + Br⁻(aq)
Br: 0 → -1
S: +6 → +4
B: +1 → +3

2. Identify the elements that are being oxidized and reduced:
Br is being reduced (from 0 to -1) and S is being oxidized (from +6 to +4)

3. Write separate half-reactions for oxidation and reduction:
Reduction: Br → Br⁻
Oxidation: S1U1B12 → BrOS1U1B13S1U1B0⁻

4. Balance each half-reaction:
Reduction: Br → Br⁻ (add 1 electron to the products) 
Oxidation: BrS1U1B12 → BrOS1U1B13S1U1B0⁻ (add 1 H2O and 2 OH⁻ to the products)

BrS1U1B12 + H2O + 2 OH⁻ → BrOS1U1B13S1U1B0⁻ + 2 electrons + 2 H2O

5. Balance the overall reaction:
Multiply the reduction half-reaction by 4 and add it to the oxidation half-reaction:
4Br + 4H2O + 8OH⁻ + BrS1U1B12 → 4Br⁻ + 4H2O + BrOS1U1B13S1U1B0⁻ + 2 electrons + 2 H2O

Cancel out the water molecules and simplify:
4Br + 8OH⁻ + BrS1U1B12 → 4Br⁻ + BrOS1U1B13S1U1B0⁻ + 2 electrons

Add 2 OH⁻ to both sides of the equation to neutralize the H⁺ produced:
4Br + 10OH⁻ + BrS1U1B12 → 4Br⁻ + BrOS1U1B13S1U1B0⁻ + 2H2O + 2 electrons

The coefficients are as follows: 
BrS1U1B12 S1U1B0 = 3
OH⁻ = 6

Question 5

Balance the following redox reaction.What are the coefficients in front of H₂O and NO in the balanced reaction? Zn(s)+ HNO₃(aq)→ Zn²⁺(aq)+ NO(g)

Accepted Answer

In the balanced reaction, the coefficients in front of H₂O and NO are 4 and 2, respectively.

Question 6

What element is being reduced in the following redox reaction? H₂O₂(l)+ ClO₂(aq)→ ClO₂⁻(aq)+ O₂(g)

Accepted Answer

In the given reaction, Cl2 (chlorine) is being reduced as it gains electrons to form Cl^- (chloride ions). The oxidation state of chlorine changes from 0 in Cl2 to -1 in Cl^-, indicating a gain of electrons, which is the definition of reduction.

Question 7

What element is being oxidized in the following redox reaction? H₂O₂(l)+ ClO₂(aq)→ ClO₂⁻(aq)+ O₂(g)

Accepted Answer

In the reaction, the oxidation state of oxygen changes from -2 in HSO3- to 0 in O2. This means oxygen is being reduced, while another element must be oxidized. The only other element present in the reaction that could be oxidized is sulfur, which goes from +4 in HSO3- to +6 in SO42-. Therefore, the element being oxidized is sulfur.

Question 8

Balance the following redox reaction if it occurs in acidic solution.What are the coefficients in front of H⁺and Fe³⁺ in the balanced reaction? Fe²⁺(aq)+ MnO₄⁻(aq)→ Fe³⁺(aq)+ Mn²⁺(aq)

Accepted Answer

The answer of Balance the following redox reaction if it...

Question 9

What element is being oxidized in the following redox reaction? MnO₄⁻(aq)+ H₂C₂O₄(aq)→ Mn²⁺(aq)+ CO₂(g)

Accepted Answer

The answer of What element is being oxidized in the...

Question 10

What element is being reduced in the following redox reaction? C₃H₈O₂(aq)+ KMnO₄(aq)→ C₃H₂O₄K₂(aq)+ MnO₂(aq)

Accepted Answer

In the given redox reaction, Mn is being reduced as it goes from a higher oxidation state in KMnO4 to a lower oxidation state in MnO2. Reduction involves a decrease in oxidation state.

Question 11

Balance the following reaction in KOH.What are the coefficients in front of H₂O and KOH in the balanced reaction and list which side of the equation that H₂O and KOH appear? C₃H₈O₂(aq)+ KMnO₄(aq)→ C₃H₂O₄K₂(aq)+ MnO₂(aq)

Accepted Answer

The answer of Balance the following reaction in KOH.What are...

Question 12

Balance the following reaction under basic conditions.What are the coefficients in front of H₂O and Cl^- in the balanced reaction? Cl₂(aq)+ Br₂(l)→ BrO₃^-(aq)+ Cl^-(aq)

Accepted Answer

In basic conditions, the balanced reaction is: 3Cl2 + 6OH- + Br2 → 2BrO3- + 6Cl- + 3H2O. Thus, the coefficients for H2O and Cl- are 6 and 10, respectively.

Question 13

What element is being reduced in the following redox reaction? C₃H₈O₂(aq)+ K₂Cr₂O₇(aq)→ C₃H₄O₄(aq)+ Cr⁺³(aq)

Accepted Answer

In the given redox reaction, chromium (Cr) is being reduced as its oxidation state decreases from +6 in K2Cr2O7 to +3 in Cr3+.

Question 14

What element is being reduced in the following redox reaction? Cr(OH)₄⁻(aq)+ ClO⁻(aq)→ CrO₄^2-(aq)+ Cl⁻(aq)

Accepted Answer

The answer of What element is being reduced in the...

Question 15

Balance the following redox reaction if it occurs in acidic solution.What are the coefficients in front of H₂C₂O₄and H₂O in the balanced reaction? MnO₄⁻(aq)+ H₂C₂O₄(aq)→ Mn²⁺(aq)+ CO₂(g)

Accepted Answer

The answer of Balance the following redox reaction if it...

Question 16

What element is being reduced in the following redox reaction? MnO₄⁻(aq)+ H₂C₂O₄(aq)→ Mn²⁺(aq)+ CO₂(g)

Accepted Answer

In the given redox reaction, Mn is being reduced as it goes from an oxidation state of +7 in MnO4- to +2 in Mn2+. Reduction involves a decrease in oxidation state.

Question 17

Balance the following redox reaction if it occurs in basic solution.What are the coefficients in front of ClO₂and H₂O in the balanced reaction? H₂O₂(l)+ ClO₂(aq)→ ClO₂⁻(aq)+ O₂(g)

Accepted Answer

The answer of Balance the following redox reaction if it...

Question 18

Balance the following redox reaction if it occurs in H₂SO₄.What are the coefficients in front of C₃H₈O₂and H₂SO₄ in the balanced reaction? C₃H₈O₂(aq)+ K₂Cr₂O₇(aq)→ C₃H₄O₄(aq)+ Cr₂(SO₄)₃(aq)

Accepted Answer

- To balance the equation, first, we need to identify which elements are being oxidized and reduced. We can do this by assigning oxidation states to each element in the equation. - In K₂Cr₂O₇(aq), the oxidation state of chromium (Cr) is +6, while in Cr₂(SO₄)₃(aq) it is +3. Therefore, Cr is being reduced from +6 to +3. - In C₃H₈O₂(aq), the oxidation state of sulfur (S) in HSO4 is +6, while in SO42- is +6. Therefore, S is not being oxidized or reduced. - We can balance the equation by adding coefficients to each compound so that the number of atoms of each element is equal on both sides of the equation. - The balanced equation is: 3CSO4^2- + 8HSO4^- + 2KCr2O7 -> 3H2SO4 + Cr2(SO4)3 + 2KSO4 - From the balanced equation, we can see that the coefficient in front of C₃H₈O₂ is 3 and the coefficient in front of H₂SO₄ is 8. Therefore, the answer is (D).

Question 19

What element is being oxidized in the following redox reaction? C₃H₈O₂(aq)+ K₂Cr₂O₇(aq)→ C₃H₄O₄(aq)+ Cr⁺³(aq)

Accepted Answer

In the reaction, carbon (C) goes from an oxidation state of +3 in $ \text{C}_2\text{H}_3\text{O}_2^- $ to +4 in $ \text{C}_2\text{H}_4\text{O}_2 $, indicating it is being oxidized.

Question 20

What element is being oxidized in the following redox reaction? Cr(OH)₄⁻(aq)+ ClO⁻(aq)→ CrO₄^2-(aq)+ Cl⁻(aq)

Accepted Answer

In the reactants, chromium has a +3 oxidation state and in the products it has a +6 oxidation state. Therefore, chromium is being oxidized, making choice A the correct answer.

Quiz 20: Electrochemistry

Balance the following redox reaction if it occurs in H₂SO₄.What are the coefficients in front of H₂O and Cr₂(SO₄) ₃ in the balanced reaction? C₃H₈O₂(aq) + K₂Cr₂O₇(aq) → C₃H₄O₄(aq) + Cr₂(SO₄) ₃(aq)

Balance the following reaction in KOH.What are the coefficients in front of C₃H₈O₂ and KMnO₄ in the balanced reaction? C₃H₈O₂(aq) + KMnO₄(aq) → C₃H₂O₄K₂(aq) + MnO₂(aq)

What element is being oxidized in the following redox reaction? C₃H₈O₂(aq) + KMnO₄(aq) → C₃H₂O₄K₂(aq) + MnO₂(aq)

Balance the following redox reaction if it occurs in basic solution.What are the coefficients in front of Br₂and OH⁻ in the balanced reaction? Br₂(l) → BrO₃⁻(aq) + Br⁻(aq)

Balance the following redox reaction.What are the coefficients in front of H₂O and NO in the balanced reaction? Zn(s) + HNO₃(aq) → Zn²⁺(aq) + NO(g)

What element is being reduced in the following redox reaction? H₂O₂(l) + ClO₂(aq) → ClO₂⁻(aq) + O₂(g)

What element is being oxidized in the following redox reaction? H₂O₂(l) + ClO₂(aq) → ClO₂⁻(aq) + O₂(g)

Balance the following redox reaction if it occurs in acidic solution.What are the coefficients in front of H⁺and Fe³⁺ in the balanced reaction? Fe²⁺(aq) + MnO₄⁻(aq) → Fe³⁺(aq) + Mn²⁺(aq)

What element is being oxidized in the following redox reaction? MnO₄⁻(aq) + H₂C₂O₄(aq) → Mn²⁺(aq) + CO₂(g)

What element is being reduced in the following redox reaction? C₃H₈O₂(aq) + KMnO₄(aq) → C₃H₂O₄K₂(aq) + MnO₂(aq)

Balance the following reaction in KOH.What are the coefficients in front of H₂O and KOH in the balanced reaction and list which side of the equation that H₂O and KOH appear? C₃H₈O₂(aq) + KMnO₄(aq) → C₃H₂O₄K₂(aq) + MnO₂(aq)

Balance the following reaction under basic conditions.What are the coefficients in front of H₂O and Cl^- in the balanced reaction? Cl₂(aq) + Br₂(l) → BrO₃^-(aq) + Cl^-(aq)

What element is being reduced in the following redox reaction? C₃H₈O₂(aq) + K₂Cr₂O₇(aq) → C₃H₄O₄(aq) + Cr⁺³(aq)

What element is being reduced in the following redox reaction? Cr(OH) ₄⁻(aq) + ClO⁻(aq) → CrO₄^2-(aq) + Cl⁻(aq)

Balance the following redox reaction if it occurs in acidic solution.What are the coefficients in front of H₂C₂O₄and H₂O in the balanced reaction? MnO₄⁻(aq) + H₂C₂O₄(aq) → Mn²⁺(aq) + CO₂(g)

What element is being reduced in the following redox reaction? MnO₄⁻(aq) + H₂C₂O₄(aq) → Mn²⁺(aq) + CO₂(g)

Balance the following redox reaction if it occurs in basic solution.What are the coefficients in front of ClO₂and H₂O in the balanced reaction? H₂O₂(l) + ClO₂(aq) → ClO₂⁻(aq) + O₂(g)

Balance the following redox reaction if it occurs in H₂SO₄.What are the coefficients in front of C₃H₈O₂and H₂SO₄ in the balanced reaction? C₃H₈O₂(aq) + K₂Cr₂O₇(aq) → C₃H₄O₄(aq) + Cr₂(SO₄) ₃(aq)

What element is being oxidized in the following redox reaction? C₃H₈O₂(aq) + K₂Cr₂O₇(aq) → C₃H₄O₄(aq) + Cr⁺³(aq)

What element is being oxidized in the following redox reaction? Cr(OH) ₄⁻(aq) + ClO⁻(aq) → CrO₄^2-(aq) + Cl⁻(aq)

Quiz 20: Electrochemistry

Balance the following redox reaction if it occurs in H2SO4.What are the coefficients in front of H2O and Cr2(SO4) 3 in the balanced reaction? C3H8O2(aq) + K2Cr2O7(aq) → C3H4O4(aq) + Cr2(SO4) 3(aq)

Balance the following reaction in KOH.What are the coefficients in front of C3H8O2 and KMnO4 in the balanced reaction? C3H8O2(aq) + KMnO4(aq) → C3H2O4K2(aq) + MnO2(aq)

What element is being oxidized in the following redox reaction? C3H8O2(aq) + KMnO4(aq) → C3H2O4K2(aq) + MnO2(aq)

Balance the following redox reaction if it occurs in basic solution.What are the coefficients in front of Br2 and OH⁻ in the balanced reaction? Br2(l) → BrO3⁻(aq) + Br⁻(aq)

Balance the following redox reaction.What are the coefficients in front of H2O and NO in the balanced reaction? Zn(s) + HNO3(aq) → Zn2+(aq) + NO(g)

What element is being reduced in the following redox reaction? H2O2(l) + ClO2(aq) → ClO2⁻(aq) + O2(g)

What element is being oxidized in the following redox reaction? H2O2(l) + ClO2(aq) → ClO2⁻(aq) + O2(g)

Balance the following redox reaction if it occurs in acidic solution.What are the coefficients in front of H⁺ and Fe3+ in the balanced reaction? Fe2+(aq) + MnO4⁻(aq) → Fe3+(aq) + Mn2+(aq)

What element is being oxidized in the following redox reaction? MnO4⁻(aq) + H2C2O4(aq) → Mn2+(aq) + CO2(g)

What element is being reduced in the following redox reaction? C3H8O2(aq) + KMnO4(aq) → C3H2O4K2(aq) + MnO2(aq)

Balance the following reaction in KOH.What are the coefficients in front of H2O and KOH in the balanced reaction and list which side of the equation that H2O and KOH appear? C3H8O2(aq) + KMnO4(aq) → C3H2O4K2(aq) + MnO2(aq)

Balance the following reaction under basic conditions.What are the coefficients in front of H2O and Cl- in the balanced reaction? Cl2(aq) + Br2(l) → BrO3-(aq) + Cl-(aq)

What element is being reduced in the following redox reaction? C3H8O2(aq) + K2Cr2O7(aq) → C3H4O4(aq) + Cr+3(aq)

What element is being reduced in the following redox reaction? Cr(OH) 4⁻(aq) + ClO⁻(aq) → CrO42-(aq) + Cl⁻(aq)

Balance the following redox reaction if it occurs in acidic solution.What are the coefficients in front of H2C2O4 and H2O in the balanced reaction? MnO4⁻(aq) + H2C2O4(aq) → Mn2+(aq) + CO2(g)

What element is being reduced in the following redox reaction? MnO4⁻(aq) + H2C2O4(aq) → Mn2+(aq) + CO2(g)

Balance the following redox reaction if it occurs in basic solution.What are the coefficients in front of ClO2 and H2O in the balanced reaction? H2O2(l) + ClO2(aq) → ClO2⁻(aq) + O2(g)

Balance the following redox reaction if it occurs in H2SO4.What are the coefficients in front of C3H8O2 and H2SO4 in the balanced reaction? C3H8O2(aq) + K2Cr2O7(aq) → C3H4O4(aq) + Cr2(SO4) 3(aq)

What element is being oxidized in the following redox reaction? C3H8O2(aq) + K2Cr2O7(aq) → C3H4O4(aq) + Cr+3(aq)

What element is being oxidized in the following redox reaction? Cr(OH) 4⁻(aq) + ClO⁻(aq) → CrO42-(aq) + Cl⁻(aq)

Balance the following redox reaction if it occurs in H₂SO₄.What are the coefficients in front of H₂O and Cr₂(SO₄) ₃ in the balanced reaction? C₃H₈O₂(aq) + K₂Cr₂O₇(aq) → C₃H₄O₄(aq) + Cr₂(SO₄) ₃(aq)

Balance the following reaction in KOH.What are the coefficients in front of C₃H₈O₂ and KMnO₄ in the balanced reaction? C₃H₈O₂(aq) + KMnO₄(aq) → C₃H₂O₄K₂(aq) + MnO₂(aq)

What element is being oxidized in the following redox reaction? C₃H₈O₂(aq) + KMnO₄(aq) → C₃H₂O₄K₂(aq) + MnO₂(aq)

Balance the following redox reaction if it occurs in basic solution.What are the coefficients in front of Br₂and OH⁻ in the balanced reaction? Br₂(l) → BrO₃⁻(aq) + Br⁻(aq)

Balance the following redox reaction.What are the coefficients in front of H₂O and NO in the balanced reaction? Zn(s) + HNO₃(aq) → Zn²⁺(aq) + NO(g)

What element is being reduced in the following redox reaction? H₂O₂(l) + ClO₂(aq) → ClO₂⁻(aq) + O₂(g)

What element is being oxidized in the following redox reaction? H₂O₂(l) + ClO₂(aq) → ClO₂⁻(aq) + O₂(g)

Balance the following redox reaction if it occurs in acidic solution.What are the coefficients in front of H⁺and Fe³⁺ in the balanced reaction? Fe²⁺(aq) + MnO₄⁻(aq) → Fe³⁺(aq) + Mn²⁺(aq)

What element is being oxidized in the following redox reaction? MnO₄⁻(aq) + H₂C₂O₄(aq) → Mn²⁺(aq) + CO₂(g)

What element is being reduced in the following redox reaction? C₃H₈O₂(aq) + KMnO₄(aq) → C₃H₂O₄K₂(aq) + MnO₂(aq)

Balance the following reaction in KOH.What are the coefficients in front of H₂O and KOH in the balanced reaction and list which side of the equation that H₂O and KOH appear? C₃H₈O₂(aq) + KMnO₄(aq) → C₃H₂O₄K₂(aq) + MnO₂(aq)

Balance the following reaction under basic conditions.What are the coefficients in front of H₂O and Cl^- in the balanced reaction? Cl₂(aq) + Br₂(l) → BrO₃^-(aq) + Cl^-(aq)

What element is being reduced in the following redox reaction? C₃H₈O₂(aq) + K₂Cr₂O₇(aq) → C₃H₄O₄(aq) + Cr⁺³(aq)

What element is being reduced in the following redox reaction? Cr(OH) ₄⁻(aq) + ClO⁻(aq) → CrO₄^2-(aq) + Cl⁻(aq)

Balance the following redox reaction if it occurs in acidic solution.What are the coefficients in front of H₂C₂O₄and H₂O in the balanced reaction? MnO₄⁻(aq) + H₂C₂O₄(aq) → Mn²⁺(aq) + CO₂(g)

What element is being reduced in the following redox reaction? MnO₄⁻(aq) + H₂C₂O₄(aq) → Mn²⁺(aq) + CO₂(g)

Balance the following redox reaction if it occurs in basic solution.What are the coefficients in front of ClO₂and H₂O in the balanced reaction? H₂O₂(l) + ClO₂(aq) → ClO₂⁻(aq) + O₂(g)

Balance the following redox reaction if it occurs in H₂SO₄.What are the coefficients in front of C₃H₈O₂and H₂SO₄ in the balanced reaction? C₃H₈O₂(aq) + K₂Cr₂O₇(aq) → C₃H₄O₄(aq) + Cr₂(SO₄) ₃(aq)

What element is being oxidized in the following redox reaction? C₃H₈O₂(aq) + K₂Cr₂O₇(aq) → C₃H₄O₄(aq) + Cr⁺³(aq)

What element is being oxidized in the following redox reaction? Cr(OH) ₄⁻(aq) + ClO⁻(aq) → CrO₄^2-(aq) + Cl⁻(aq)