Question 1

Identify the location of reduction in an electrochemical cell.

Accepted Answer

Reduction occurs at the cathode in an electrochemical cell.

Question 2

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

Accepted Answer

The element that is being oxidized is O (oxygen), which is going from an oxidation state of -2 in HSO3- to 0 in O2.

Question 3

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. Write the unbalanced equation:
BrS1U1B12S1U1B0(l) → BrOS1U1B13S1U1B0⁻(aq) + Br⁻(aq)
2. Identify the oxidation states of each element and determine which atoms are being oxidized and reduced:
Br: 0 → -1 (oxidized)
S1U1B0: -2 → -1 (reduced)
3. Balance the equation for the reduced atom (S1U1B0) first by adding H2O:
BrS1U1B12S1U1B0(l) + H2O → BrOS1U1B13S1U1B0⁻(aq) + Br⁻(aq)
4. Add OH- ions to each side to neutralize the H+ ions:
BrS1U1B12S1U1B0(l) + H2O + OH- → BrOS1U1B13S1U1B0⁻(aq) + Br⁻(aq) + OH-
5. Balance the oxygen atoms by adding H2O on the right side:
BrS1U1B12S1U1B0(l) + H2O + OH- → BrOS1U1B13S1U1B0⁻(aq) + Br⁻(aq) + H2O
6. Balance the hydrogen atoms by adding H+ ions on the left side:
BrS1U1B12S1U1B0(l) + 2H2O + OH- → BrOS1U1B13S1U1B0⁻(aq) + Br⁻(aq) + H2O + H+
7. Balance the charges by adding electrons (e-) to the side with the higher positive charge. In this case, the left side has a higher positive charge, so add 2 e- to that side:
BrS1U1B12S1U1B0(l) + 2H2O + OH- + 2e- → BrOS1U1B13S1U1B0⁻(aq) + Br⁻(aq) + H2O + H+
8. Multiply each half-reaction by the appropriate coefficient to have the same number of electrons. In this case, the electrons cancel out without needing any multipliers.
9. Combine the half-reactions, canceling out any species that appear on both sides. The final balanced equation is:
3BrS1U1B12S1U1B0(l) + 8H2O + 6OH- → 3BrOS1U1B13S1U1B0⁻(aq) + 4Br⁻(aq) + 6H2O

The coefficients in front of BrS1U1B12S1U1B0 and OH- are 3 and 6, respectively. Therefore the answer is D.

Question 4

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

Accepted Answer

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

Question 5

What element is being reduced in the following (unbalanced)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 6

What element is being oxidized in the following (unbalanced)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. Hence, chromium is being oxidized and the correct answer is A.

Question 7

Balance the following redox reaction if it occurs in basic solution. What are the coefficients in front of Cr(OH)₄⁻and ClO⁻ in the balanced reaction? Cr(OH)₄⁻(aq)+ ClO⁻(aq)→ CrO₄^2-(aq)+ Cl⁻(aq)

Accepted Answer

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

Question 8

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 9

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

First, separate the reaction into half-reactions: Fe²⁺ → Fe³⁺ Balance the hydrogen with H⁺: Fe²⁺ + H⁺ → Fe³⁺ Balance the charge with electrons: Fe²⁺ + H⁺ + 2e⁻ → Fe³⁺ and MnO₄⁻ → Mn²⁺ Balance the oxygen with H₂O: MnO₄⁻ + H₂O → Mn²⁺ Balance the hydrogen with H⁺: MnO₄⁻ + H₂O + H⁺ → Mn²⁺ Balance the charge with electrons: MnO₄⁻ + H₂O + H⁺ + 2e⁻ → Mn²⁺ Then, multiply the half-reactions by the appropriate coefficients to balance the number of electrons. In this case, we need 5 electrons on the left side and 5 electrons on the right side. This is achieved by multiplying the first half-reaction by 5 and the second half-reaction by 2: 5Fe²⁺ + 5H⁺ + 10e⁻ → 5Fe³⁺ 2MnO₄⁻ + 2H₂O + 2H⁺ + 4e⁻ → 2Mn²⁺ Now add the half-reactions together: 5Fe²⁺ + 5H⁺ + 2MnO₄⁻ + 2H₂O + 2H⁺ + 10e⁻ + 4e⁻ → 5Fe³⁺ + 2Mn²⁺ Simplify and cancel out the electrons: 5Fe²⁺ + 7H⁺ + 2MnO₄⁻ → 5Fe³⁺ + 2Mn²⁺ Finally, count the coefficients in front of each species to answer the question: H⁺ = 7, Fe³⁺= 5 (closest to the correct answer is B, with H⁺ = 8 and Fe³⁺= 5).

Question 10

Balance the following redox reaction if it occurs in acidic solution. What are the coefficients in front of Cdand Ag⁺ in the balanced reaction? Cd(s)+ Ag⁺(aq)→ Ag(s)+ Cd²⁺(aq)

Accepted Answer

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

Question 11

What element is being oxidized in the following (unbalanced)redox reaction? Zn²⁺(aq)+ NH₄⁺(aq)→ Zn(s)+ NO₃⁻(aq)

Accepted Answer

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

Question 12

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 13

Which of the following statements is TRUE?

Accepted Answer

An oxidation process involves the loss of electrons resulting in an increase in oxidation state. This can be remembered using the mnemonic OIL RIG (oxidation is loss of electrons, reduction is gain of electrons).

Question 14

Determine the redox reaction represented by the following cell notation: Mg(s)∣ Mg²⁺(aq) Cu²⁺(aq)∣ Cu(s)

Accepted Answer

The cell notation can be interpreted as Mg being oxidized to Mg ions (Mg(s) → Mg²⁺(aq)), while at the same time, Cu ions (Cu²⁺(aq) → Cu(s)) are being reduced to Cu. This means that Mg is the reducing agent, and Cu is the oxidizing agent. Therefore, the correct balanced equation is Mg(s) + Cu²⁺(aq) → Cu(s) + Mg²⁺(aq).

Question 15

Define a salt bridge.

Accepted Answer

A salt bridge is a pathway through which counterions can flow between the half-cells without the solutions in the half-cell totally mixing. This maintains electrical neutrality in the half-cells and allows for the continued flow of electrons in the electrochemical cell. Option A is incorrect because a salt bridge does not necessarily have to be composed of salt water. Option B is incorrect because ions do flow through a salt bridge. Options C and D are incorrect because the ions in the salt bridge do not participate in the reduction or oxidation reactions at the cathode and anode.

Question 16

Balance the following redox reaction if it occurs in acidic solution. What are the coefficients in front of Znand H⁺ in the balanced reaction? Zn²⁺(aq)+ NH₄⁺(aq)→ Zn(s)+ NO₃⁻(aq)

Accepted Answer

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

Question 17

Balance the following redox reaction if it occurs in basic solution. What are the coefficients in front of Aland F₂ in the balanced reaction? Al(s)+ F₂(g)→ Al³⁺(aq)+ F^-(aq)

Accepted Answer

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

Question 18

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

Accepted Answer

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

Question 19

Identify the location of oxidation in an electrochemical cell.

Accepted Answer

Oxidation occurs at the anode in an electrochemical cell, where electrons are lost from the species being oxidized. The cathode is where reduction occurs, where electrons are gained by the species being reduced. The electrode and salt bridge are both components of the cell, but do not directly relate to oxidation. The socket is not a component of an electrochemical cell.

Question 20

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

Accepted Answer

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

Quiz 18: Electrochemistry

Identify the location of reduction in an electrochemical cell.

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

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)

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

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

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

Balance the following redox reaction if it occurs in basic solution. What are the coefficients in front of Cr(OH) ₄⁻and ClO⁻ in the balanced 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)

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)

Balance the following redox reaction if it occurs in acidic solution. What are the coefficients in front of Cdand Ag⁺ in the balanced reaction? Cd(s) + Ag⁺(aq) → Ag(s) + Cd²⁺(aq)

What element is being oxidized in the following (unbalanced) redox reaction? Zn²⁺(aq) + NH₄⁺(aq) → Zn(s) + NO₃⁻(aq)

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)

Which of the following statements is TRUE?

Determine the redox reaction represented by the following cell notation: Mg(s) ∣ Mg²⁺(aq) Cu²⁺(aq) ∣ Cu(s)

Define a salt bridge.

Balance the following redox reaction if it occurs in acidic solution. What are the coefficients in front of Znand H⁺ in the balanced reaction? Zn²⁺(aq) + NH₄⁺(aq) → Zn(s) + NO₃⁻(aq)

Balance the following redox reaction if it occurs in basic solution. What are the coefficients in front of Aland F₂ in the balanced reaction? Al(s) + F₂(g) → Al³⁺(aq) + F^-(aq)

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

Identify the location of oxidation in an electrochemical cell.

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

Quiz 18: Electrochemistry

Identify the location of reduction in an electrochemical cell.

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

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)

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

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

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

Balance the following redox reaction if it occurs in basic solution. What are the coefficients in front of Cr(OH) 4⁻ and ClO⁻ in the balanced 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)

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)

Balance the following redox reaction if it occurs in acidic solution. What are the coefficients in front of Cd and Ag+ in the balanced reaction? Cd(s) + Ag+(aq) → Ag(s) + Cd2+(aq)

What element is being oxidized in the following (unbalanced) redox reaction? Zn2+(aq) + NH4+(aq) → Zn(s) + NO3⁻(aq)

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)

Which of the following statements is TRUE?

Determine the redox reaction represented by the following cell notation: Mg(s) ∣ Mg2+(aq) Cu2+(aq) ∣ Cu(s)

Define a salt bridge.

Balance the following redox reaction if it occurs in acidic solution. What are the coefficients in front of Zn and H+ in the balanced reaction? Zn2+(aq) + NH4+(aq) → Zn(s) + NO3⁻(aq)

Balance the following redox reaction if it occurs in basic solution. What are the coefficients in front of Al and F2 in the balanced reaction? Al(s) + F2(g) → Al3+(aq) + F-(aq)

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

Identify the location of oxidation in an electrochemical cell.

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

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

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)

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

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

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

Balance the following redox reaction if it occurs in basic solution. What are the coefficients in front of Cr(OH) ₄⁻and ClO⁻ in the balanced 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)

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)

Balance the following redox reaction if it occurs in acidic solution. What are the coefficients in front of Cdand Ag⁺ in the balanced reaction? Cd(s) + Ag⁺(aq) → Ag(s) + Cd²⁺(aq)

What element is being oxidized in the following (unbalanced) redox reaction? Zn²⁺(aq) + NH₄⁺(aq) → Zn(s) + NO₃⁻(aq)

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)

Determine the redox reaction represented by the following cell notation: Mg(s) ∣ Mg²⁺(aq) Cu²⁺(aq) ∣ Cu(s)

Balance the following redox reaction if it occurs in acidic solution. What are the coefficients in front of Znand H⁺ in the balanced reaction? Zn²⁺(aq) + NH₄⁺(aq) → Zn(s) + NO₃⁻(aq)

Balance the following redox reaction if it occurs in basic solution. What are the coefficients in front of Aland F₂ in the balanced reaction? Al(s) + F₂(g) → Al³⁺(aq) + F^-(aq)

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

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