Balancing Redox Reactions Chemistry

Redox Reactions Review

Assigning Oxidation Numbers

Multiple Choice

Another name for a "oxidation-reduction" reaction is

• chemical reaction
• neutralization reaction
• redox reaction
• nuclear reaction

Multiple Choice

What is the oxidation number of N in NO_2^-1?

• -3
• +4
• -2
• +3

Multiple Choice

What is oxidation number of O in O₂ ?

• 0
• -2
• +1
• +2

Multiple Choice

What is oxidation number of Fe in FeO ?

• +2
• -2
• 0
• +1

Multiple Choice

What is oxidation number of H in CaH₂?

• +1
• -1
• 0
• +2

Multiple Choice

What is oxidation number of Cr in Cr₂O_7^2-?

• -2
• +2
• +6
• +12

Multiple Choice

What is oxidation number of H in H₂O?

• 0
• -2
• -1
• +1

Identifying Reduction and Oxidation

LEO GER

Multiple Choice

What element is being reduced?

• I
• H
  H
• S
  S
• O
  O

Multiple Choice

What element is being Reduced?

• N
• H
• O
• S

Multiple Choice

What element is being Oxidized?

• N
• H
• O
• S

Multiple Choice

This is the half reaction for: 
Sn(s) → Sn⁴⁺(aq) + 4e⁻

• redox
• reduction
• oxidation
• neutralization

Multiple Choice

In any redox reaction, the substance that undergoes reduction will

• lose electrons and have a decrease in oxidation number

• lose electrons and have an increase in oxidation number

• gain electrons and have a decrease in oxidation number

• gain electrons and have an increase in oxidation number

Multiple Choice

Which reaction is an example of an oxidation-reduction reaction?

• AgNO₃ + KI --> AgI + KNO₃

• Cu + 2 AgNO₃ --> Cu(NO₃)₂ + 2 Ag

• 2 KOH + H₂SO₄ -> K₂SO₄ + 2 H₂O

• Ba(OH)2 + 2 HCl --> BaCl2 + 2 H2O

Multiple Choice

Which half-reaction correctly represents reduction?

• Ag --> Ag⁺ + e^-

• F₂ --> 2 F^- + 2e^-

• Au³⁺ + 3e^- --> Au

• Fe²⁺ + e^- --> Fe³⁺

Balancing Redox Reactions

Multiple Choice

WRITE THIS OUT ON PAPER, YOU MAY USE THE ANSWER TO THIS PROBLEM AGAIN IN ANOTHER QUESTION:

Balance the following ACIDIC reactions using the half-reaction method.

MnO₄⁻(aq) + H⁺(aq) + I⁻ (aq) → Mn²⁺(aq) + I₂(s)

Water is a product of this reaction. What is the coefficient of water in the final balanced equation?

• 8

• 5

• 2

• 16

Multiple Choice

WRITE THIS OUT ON PAPER, YOU MAY USE THE ANSWER TO THIS PROBLEM AGAIN IN ANOTHER QUESTION:

Balance the following reactions using the half-reaction method.

MnO₄⁻(aq) + H⁺(aq) + I⁻ (aq) → Mn²⁺(aq) + I₂(s)

How many electrons did you cross out on both side?

• 1 e^-

• 2 e^-

• 5 e^-

• 10 e^-

Multiple Choice

WRITE THIS OUT ON PAPER, YOU MAY USE THE ANSWER TO THIS PROBLEM AGAIN IN ANOTHER QUESTION:

Consider the following REDOX reaction:

Cl₂(g) → ClO⁻(aq) + Cl⁻(aq) (basic solution)

How many OH^- molecules did you add to the reactant side of this reaction when balancing?

• 1

• 2

• 3

• 4

Multiple Choice

WRITE THIS OUT ON PAPER, YOU MAY USE THE ANSWER TO THIS PROBLEM AGAIN IN ANOTHER QUESTION:

Consider the following REDOX reaction:

Cl₂(g) → ClO⁻(aq) + Cl⁻(aq) (basic solution)

Which species is the result of oxidation?

• Cl⁻

• ClO⁻