Unit 8 Electrochemistry Assessment

In a voltaic cell electrons flow from

• the anode to the cathode

• the cathode to the anode

• From the cation to the anion

• from the cation to the electrolytes

The anode is the negative electrode in a voltaic cell, it is the site of

• oxidation and reduction

• oxidation

• reduction

• electrolysis

When comparing voltaic cells to electrolytic cells, oxidation occurs at the

• anode in both types of cells

• cathode in both types of cells

• anode in voltaic cells, only

• cathode in voltaic cells, only

Based on Table J, which metal is more active than tin, but less active than zinc?

• Ag

• Cs

• Cr

• Mn

Given 2H₂O → O₂(g) + 2H₂(g)

State the change in oxidation number that occurs for oxygen in the overall reaction

Compare the number of electrons lost by oxygen to the number of electrons gained by hydrogen in the overall reaction in question 5 above.

Which statement describes the reactions in an electrochemical cell?

• Oxidation occurs at the anode, and reduction occurs at the cathode

• Oxidation occurs at the cathode, and reduction occurs at the anode.

• Oxidation and reduction both occur at the cathode.

• Oxidation and reduction both occur at the anode.

Which equation represents a spontaneous reaction?

• Ca + Ba²⁺ → Ca²⁺ + Ba

• Co + Zn²⁺ → Co²⁺ + Zn

• Fe + Mg²⁺ → Fe2⁺ + Mg

• Mn + Ni²⁺ → Mn²⁺ + Ni

Given 3Cu²⁺(aq) + 2Cr(s) → 3Cu(s) + 2Cr³⁺(aq)

Write a reduction equation for the half-reaction

State the purpose of the salt bridge in completing the circuit in a voltaic cell