Deck 17: Electrochemistry

Question 1

Electron flow in a voltaic cell is always from _____ to _____. Outcome # 10) DOK 2)

A) anode to cathode
B) cathode to anode
C) anode to negative terminal

Answer 1

anode to cathode

Question 2

Automobiles from northern states tend to show more signs of rust formation than southern states. The reason for this is that the rate of corrosion is affected by _____, which is more common during winter months especially in northern states. Outcome # 6) DOK 1)

A) the cold air and clouds
B) rain clouds
C) snow, ice, and salt mixtures

Answer 2

snow, ice, and salt mixtures

Question 3

In a voltaic cell, electrons are produced at the _____. Outcome # 10) DOK 1)

A) positive terminal
B) anode terminal
C) cathode terminal

Answer 3

anode terminal

Question 4

In a voltaic cell, reduction occurs at the _____. Outcome # 10) DOK 1)

A) anode terminal
B) cathode terminal
C) negative terminal

Question 5

Propane is used as a fuel source on many barbeque grills. What is undergoing oxidation during the burning of propane while grilling? Outcome # 6) DOK 3)

A) CH₃CH₂CH₃
B) O₂
C) CO₂

Question 6

The anode terminal in a voltaic cell is the _____ terminal. Outcome # 10) DOK 1)

A) -)
B) +)
C) Neutral

Question 7

Based on the reduction potential data, what is the standard cell potential for the following electrochemical cell reaction: Cus) + 2Ag⁺ $\rightarrow$ Cu²⁺aq) + 2Ags)? Paired item 1) E°_red = +0.800 V for Ag⁺aq) + e^- $\rightarrow$ Ags)
E°_red = +0.340 V for Cu²⁺aq) + 2e^- $\rightarrow$ Cus)

A) +1.14 V
B) +0.460 V
C) +1.26 V

Question 8

The following can be used as an electrolyte for a salt bridge in a voltaic cell? Outcome # 10) DOK 1)

A) KNO₃aq)
B) H₂Ol)
C) CH₃OHl)

Question 9

Certain anaerobic organisms such as methanogens have the ability to metabolize carbon dioxide into methane in the presence of hydrogen. Methane is produced by the oxidation of _____? Outcome # 6) DOK 3)

A) H₂
B) CO₂
C) CH₄

Question 10

Based on the reduction potential data, what is the standard cell potential for the following electrochemical cell reaction: Zns) + Cu²⁺aq) $\rightarrow$ Zn²⁺aq) + Cus)? E°_red = -0.763 V for Zn²⁺aq) + 2e^- $\rightarrow$ Zns)
E°_red = +0.340 V for Cu²⁺aq) + 2e^- $\rightarrow$ Cus)

A) +1.103 V
B) -0.423 V
C) +0.423 V

Question 11

Write a balanced redox reaction for the formation of rust on iron metal and identify the correct oxidizing agent and/or reducing agent. Outcome # 6) DOK 3)

A) Iron is the oxidizing agent and O₂ is neither a reducing agent nor an oxidizing agent
B) Iron is the oxidizing agent and O₂ is the reducing agent
C) Iron is the reducing agent and O₂ is the oxidizing agent

Question 12

The cathode terminal in a voltaic cell is the _____ terminal. Outcome # 10) DOK 1)

A) -)
B) +)
C) neutral

Question 13

The following can be used as an electrolyte for a salt bridge in a voltaic cell? Outcome # 10) DOK 1) Paired item 1)

A) CCl₄l)
B) CH₃CH₂OHl)
C) Na₂SO₄aq)

Question 14

Which is the reducing agent in the combustion of methanol? Outcome # 6) DOK 3)

A) CH₃OH
B) O₂
C) CO₂

Question 15

Based on the following reduction potential data, which is the strongest reducing agent? E°_red = +1.78 V for H₂O₂aq) + 2H⁺aq) + 2e- $\rightarrow$ 2H₂Ol)
E°_red = +0.800 V for Ag⁺aq) + e^- $\rightarrow$ Ags)
E°_red = -0.130 V for Pb²⁺aq) + 2e^- $\rightarrow$ Pbs)

A) Pbs)
B) Ags)
C) H₂Ol)

Question 16

Propane is used as a fuel source on many barbeque grills. What is undergoing reduction during the burning of propane while grilling? Outcome # 6) DOK 3) Paired item 1)

A) CH₃CH₂CH₃
B) O₂
C) CO₂

Question 17

In a voltaic cell, oxidation occurs at the _____. Outcome # 10) DOK 1)

A) anode terminal
B) cathode terminal
C) positive terminal

Question 18

A voltaic cell must be split into two separate cells, an oxidation and reduction half-cells. The two half-cells must be connected by a _____ so ions can freely flow between the two half-cells to balance the charges or the voltaic cell cannot function. Outcome # 10) DOK 2)

A) metallic wire
B) salt bridge
C) membrane

Question 19

Which is the oxidizing agent in the combustion of methanol? Outcome # 6) DOK 3)

A) CH₃OH
B) O₂
C) CO₂

Question 20

In a voltaic cell, electrons are received at the _____. Outcome # 10) DOK 1)

A) cathode terminal
B) negative terminal
C) anode terminal

Question 21

The standard cell potential is +0.460 V for the following electrochemical cell reaction: Cus) + 2Ag⁺aq) $\rightarrow$ Cu²⁺aq) + 2Ags). What is the ∆G°_rxn?

A) -88.8 kJ/mol
B) -44.4 kJ/mol
C) +44.4 kJ/mol

Question 22

Which of the following acids is a strong oxidant? Outcome # 5) DOK 1)

A) HCl
B) HNO₃
C) HI

Question 23

Which of the following is a strong oxidizing agent? Outcome # 2) DOK 2)

A) N₂
B) O₂
C) H₂

Question 24

The process of corrosion involves what type of reaction? Outcome # 2) DOK 2)

A) double displacement reaction
B) acid-base reaction
C) redox reaction

Question 25

Based on the following reduction potential data, what is the ∆G°_rxn for the following electrochemical cell reaction: Zns) + Cu²⁺aq) $\rightarrow$ Zn²⁺aq) + Cus)? E°_red = -0.763 V for Zn²⁺aq) + 2e^- $\rightarrow$ Zns)
E°_red = +0.340 V for Cu²⁺aq) + 2e^- $\rightarrow$ Cus)

A) +106 kJ/mol
B) -106 kJ/mol
C) -213 kJ/mol

Question 26

Based on the following reduction potential data, which is the strongest oxidizing agent? E°_red = +1.78 V for H₂O₂aq) + 2H⁺aq) + 2e^- $\rightarrow$ 2H₂Ol)
E°_red = +0.800 V for Ag⁺aq) + e^- $\rightarrow$ Ags)
E°_red = -0.130 V for Pb²⁺aq) + 2e^- $\rightarrow$ Pbs)

A) Pb²⁺aq)
B) H₂O₂aq)
C) Ag⁺aq)

Question 27

What is the oxidation state of oxygen in K₂O₂? Outcome # 2) DOK 2)

A) 0
B) -1
C) -2

Question 28

Cell phones batteries are typically rechargeable. How do they differ from non-rechargeable batteries? Outcome # 2) DOK 3)

A) A rechargeable battery has the ability to undergo a double replacement reaction while non-rechargeable batteries do not. Therefore, the forward direction provides electrical energy and connecting the battery to a charger reverses the reaction to reform the starting the materials.
B) A rechargeable battery has the ability to undergo a reversible redox reaction while non-rechargeable batteries do not. Therefore, the forward direction provides electrical energy and connecting the battery to a charger reverses the reaction to reform the starting the materials.
C) A rechargeable battery has the ability to undergo a redox reaction while non-rechargeable batteries do not. Therefore, the reverse direction provides electrical energy and connecting the battery to a charger reverses the reaction to reform the starting the materials.

Question 29

What is the ∆G°_rxn for a 2 electron transfer electrochemical cell with a standard cell potential of +0.770 V. Outcome # 11) DOK 2)

A) -74.3 kJ/mol
B) -149 kJ/mol
C) +74.3 kJ/mol

Question 30

Which strong acid is commonly used in automobile batteries? Outcome # 2) DOK 2)

A) HCl
B) H₂SO₄
C) HNO₃