Voltaic Cell

An electrochemical cell that generates electricity contains half-cells that produce:

• oxidation half-reactions, only

• reduction half-reactions, only

• spontaneous redox reactions

• nonspontaneous redox reactions

A standard zinc half-cell is connected to a standard copper half cell by means of a wire and a salt bridge. Which electrochemical reaction represents the oxidation reaction that takes place?

• Cu⁺ → Cu²⁺ +e

• Cu²⁺ +2e → Cu⁰

• Zn⁰ → Zn²⁺ +2e

• Zn²⁺ +2e → Zn⁰

Given the overall cell reaction: Zn(s) + 2 Ag⁺(aq) → Zn²⁺(aq) + 2 Ag(s), which will occur as the cell operates?

• The amount of Zn(s) will increase.

• The amount of Ag(s) will decrease.

• The concentration of Zn²⁺(aq) will increase.

• The concentration of Ag⁺(aq) will increase.

Tags

NGSS.HS-PS1-5

In a chemical cell composed of two half-cells, ions are allowed to flow from one half-cell to another by means of:

• electrodes

• a voltmeter

• an external conductor

• a salt bridge

Which statement is true for any electrochemical cell?

• Oxidation occurs at the anode, only.

• Reduction occurs at the anode, only.

• Oxidation occurs at both the anode and the cathode.

• Reduction occurs at both the anode and the cathode.

Tags

NGSS.HS-PS2-5

The electricity produced by a battery results from

• an oxidation reaction, only

• a reduction reaction, only

• both an oxidation reaction and a reduction reaction

• neither an oxidation reaction nor a reduction reaction

Given the nickel oxide-cadmium reaction in Ni-Cd battery: 2 Ni(OH)₃ + Cd + 2 H₂O → 2 Ni(OH)₂ + Cd(OH)₂, during discharge, the Cd electrode

• is oxidized

• is reduced

• gains electrons

• gains mass

What is the purpose of the salt bridge in a voltaic cell?

• It blocks the flow of electrons

• It blocks the flow of positive and negative ions

• It is a path for the flow of electrons

• It is a path for the flow of positive and negative ions

Which component of an electrochemical cell is correctly paired with its function?

• external conductor – allows the solutions to mix

• external conductor – permits the migration of ions

• salt bridge – allows the solutions to mix

• salt bridge – permits the migration of ions

An electrochemical setup consists of two half-cells, an anode, a cathode, an external circuit, and a salt bridge. When a reaction occurs, ions migration takes place through the:

• anode

• cathode

• salt bridge

• external circuit