CHEM 104 Module 5 | General Chemistry II w/ Lab Exam
Q&A | Portage Learning
These are original practice questions written for study. They are not official CHEM
104, Portage Learning, or university exam questions and are not copied from any
copyrighted question bank. They cover common CHEM 104 Module 5 |
Electrochemistry topics: redox reactions, oxidation numbers, galvanic cells, standard
reduction potentials, Nernst equation, electrolysis, batteries, corrosion, and clinical
applications.
Question 1:
Which process involves the loss of electrons?
A. Reduction
B. Oxidation
C. Neutralization
D. Precipitation
Correct answer: B
Rationale: Oxidation is the loss of electrons, often remembered by the mnemonic OIL
RIG.
Question 2:
Which process involves the gain of electrons?
A. Oxidation
B. Reduction
C. Sublimation
D. Combustion
Correct answer: B
Rationale: Reduction is the gain of electrons.
Question 3:
In a redox reaction, the oxidizing agent:
A. Gains electrons and is reduced
B. Loses electrons and is oxidized
C. Is always oxygen
D. Does not change
,Correct answer: A
Rationale: The oxidizing agent accepts electrons and is itself reduced.
Question 4:
In a redox reaction, the reducing agent:
A. Gains electrons
B. Loses electrons and is oxidized
C. Is always hydrogen
D. Precipitates
Correct answer: B
Rationale: The reducing agent donates electrons and is itself oxidized.
Question 5:
What is the oxidation number of oxygen in most compounds?
A. −2
B. +2
C. −1
D. 0
Correct answer: A
Rationale: Oxygen typically has an oxidation number of −2 in compounds, except
peroxides.
Question 6:
What is the oxidation number of hydrogen in metal hydrides?
A. +1
B. −1
C. 0
D. +2
Correct answer: B
Rationale: In metal hydrides, hydrogen has an oxidation number of −1.
Question 7:
What is the oxidation number of an element in its elemental form?
A. 0
B. +1
, C. −1
D. Depends on the element
Correct answer: A
Rationale: Elements in their standard states have an oxidation number of 0.
Question 8:
What is the oxidation number of Mn in MnO₄⁻?
A. +7
B. +6
C. +4
D. +2
Correct answer: A
Rationale: O is −2 × 4 = −8; overall charge is −1, so Mn must be +7.
Question 9:
What is the oxidation number of Cr in Cr₂O₇²⁻?
A. +6
B. +3
C. +7
D. +12
Correct answer: A
Rationale: O is −2 × 7 = −14; overall charge is −2, so 2Cr = +12 and Cr = +6.
Question 10:
In the reaction 2H₂ + O₂ → 2H₂O, which species is oxidized?
A. H₂
B. O₂
C. H₂O
D. None
Correct answer: A
Rationale: Hydrogen goes from 0 to +1, so it is oxidized.
Question 11:
In the reaction Zn + Cu²⁺ → Zn²⁺ + Cu, which species is the oxidizing agent?
A. Zn
Q&A | Portage Learning
These are original practice questions written for study. They are not official CHEM
104, Portage Learning, or university exam questions and are not copied from any
copyrighted question bank. They cover common CHEM 104 Module 5 |
Electrochemistry topics: redox reactions, oxidation numbers, galvanic cells, standard
reduction potentials, Nernst equation, electrolysis, batteries, corrosion, and clinical
applications.
Question 1:
Which process involves the loss of electrons?
A. Reduction
B. Oxidation
C. Neutralization
D. Precipitation
Correct answer: B
Rationale: Oxidation is the loss of electrons, often remembered by the mnemonic OIL
RIG.
Question 2:
Which process involves the gain of electrons?
A. Oxidation
B. Reduction
C. Sublimation
D. Combustion
Correct answer: B
Rationale: Reduction is the gain of electrons.
Question 3:
In a redox reaction, the oxidizing agent:
A. Gains electrons and is reduced
B. Loses electrons and is oxidized
C. Is always oxygen
D. Does not change
,Correct answer: A
Rationale: The oxidizing agent accepts electrons and is itself reduced.
Question 4:
In a redox reaction, the reducing agent:
A. Gains electrons
B. Loses electrons and is oxidized
C. Is always hydrogen
D. Precipitates
Correct answer: B
Rationale: The reducing agent donates electrons and is itself oxidized.
Question 5:
What is the oxidation number of oxygen in most compounds?
A. −2
B. +2
C. −1
D. 0
Correct answer: A
Rationale: Oxygen typically has an oxidation number of −2 in compounds, except
peroxides.
Question 6:
What is the oxidation number of hydrogen in metal hydrides?
A. +1
B. −1
C. 0
D. +2
Correct answer: B
Rationale: In metal hydrides, hydrogen has an oxidation number of −1.
Question 7:
What is the oxidation number of an element in its elemental form?
A. 0
B. +1
, C. −1
D. Depends on the element
Correct answer: A
Rationale: Elements in their standard states have an oxidation number of 0.
Question 8:
What is the oxidation number of Mn in MnO₄⁻?
A. +7
B. +6
C. +4
D. +2
Correct answer: A
Rationale: O is −2 × 4 = −8; overall charge is −1, so Mn must be +7.
Question 9:
What is the oxidation number of Cr in Cr₂O₇²⁻?
A. +6
B. +3
C. +7
D. +12
Correct answer: A
Rationale: O is −2 × 7 = −14; overall charge is −2, so 2Cr = +12 and Cr = +6.
Question 10:
In the reaction 2H₂ + O₂ → 2H₂O, which species is oxidized?
A. H₂
B. O₂
C. H₂O
D. None
Correct answer: A
Rationale: Hydrogen goes from 0 to +1, so it is oxidized.
Question 11:
In the reaction Zn + Cu²⁺ → Zn²⁺ + Cu, which species is the oxidizing agent?
A. Zn
