Question

Which of the following is the balanced net ionic equation for an oxidation-reduction reaction between ag (aq) and ni(s) based on the half-reactions represented above?

Ni(s) → Ni²+(aq) + 2e
Ag (aq) +e → Ag(s)
a. Ag+ (aq) + Ni(s) → Ag(s) + Ni²+(aq)
b. 2 Ag+ (aq) + Ni(s) → Ag(s) + 2Ni2+
c. Ag+(aq) + 2Ni(s) → Ag(s) + 2NiZ+(aq)
d. 2Ag+(aq) + Ni(s) → 2Ag(s) + Ni²+(aq)

Answer 1

Answer: D

Explanation: Firstly, you have to complete the charge. You have to get e equal to 2e. So you multiply the second line by 2. Therefore you get

2Ag+ 2e>2Ag. And the Ni line would stay the same. Therefore you combine the elements from before the arrow and then combine the elements after the arrow. Therefore, you get answer D.