Question

Write a balanced overall reaction from these unbalanced half-reactions.

Answer 1

The first half reaction is:
Sn+  ->  Sn2+

You add 1 electron on the right side:
Sn+  ->  Sn2+ + 1e-

The second half reacation is:
Ag+  -> Ag

You add 1 electron to the left side:
Ag+  +  1e-  -> Ag

Then, you combine both reactions to get the balanced overall reaction since both half reactions have 1 electrons on the right and left side, respectively. You get:
Sn+  +  Ag+  ->  Sn2+  + Ag

Answer 2

Answer: Sn + 2Ag⁺ → Sn²⁺ + 2 Ag

Explanation:

1) The half-reactions given are:

Sn → Sn²⁺

Ag⁺ → Ag

2) The first step that you should perform is to complete each half reaction with electrons to balance the charges. This is how:

Sn → Sn²⁺ + 2e⁻

Ag⁺ + 1e⁻ → Ag

3) The second step is to multiply the half-reactions by the appropiate coefficients to make the electrons on both reactions equal.

So, multiply the second reaction by 2:

Sn → Sn²⁺ + 2e⁻

2Ag⁺ + 2e⁻ → 2Ag

4) The third step is to add up the two equations:

Sn + 2Ag⁺ + 2e⁻ → Sn²⁺ + 2e⁻ + 2 Ag

5) Fourth step, cancell the electrons on both sides:

Sn + 2Ag⁺ → Sn²⁺ + 2 Ag

And that is the final answer.