Consider the following two redox reactions without any companion counterions:

Question

1. Cr_(s) --> Cr³⁺ + 3e^- oxidation half
2. Ag_(s) --> Ag⁺ + e^- reduction half

A) Write a balanced overall redox reaction where Cr is oxidized and Ag is reduced. Show work with cancelling of electrons in both product and reactant.

B) Rewrite the balanced equation but now include chloride as a spectator anion to charge balance the reactants and products (AgCl as reactant and CrCl₃ as product.)

C) The net result of this redox reaction is the conversion of which solid metal to which other solid metal?

Answer 1

Cr(s) ==> Cr³⁺ + 3e- ... oxidation

Ag⁺ +e- ==> Ag(s) ... reduction

(A) To balance the electrons, we multiply the reduction reaction by 3, and then add the two half reactions:

Cr(s) ===> Cr³⁺ + 3e-

3Ag⁺ + 3e- ==> 3Ag(s)

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Cr(s) + 3Ag⁺ ===> Cr³⁺ + 3Ag(s) ... overall reaction

(B) Cr + 3AgCl ===> CrCl₃ + 3Ag

(C) It converts solid chromium to solid silver