Question

By the use of half equation method give a balanced equation for Zn + Ag^+=Zn^2+ +Ag

Answer 1

To balance the given reaction using half-equation methods, we can break it down into two half-reactions: one for the oxidation and one for the reduction.

### Given reaction:
\[ \text{Zn} + \text{Ag}^+ \rightarrow \text{Zn}^{2+} + \text{Ag} \]

### Step 1: Identify the half-reactions

1. **Oxidation half-reaction** (Zinc is oxidized):
\[
\text{Zn} \rightarrow \text{Zn}^{2+} + 2e^-
\]
Here, zinc (Zn) loses 2 electrons to become zinc ions (\( \text{Zn}^{2+} \)).

2. **Reduction half-reaction** (Silver ion is reduced):
\[
\text{Ag}^+ + e^- \rightarrow \text{Ag}
\]
Here, silver ion (\( \text{Ag}^+ \)) gains 1 electron to become solid silver (Ag).

### Step 2: Balance the electrons

Now we need to balance the number of electrons transferred in both half-reactions. The oxidation of zinc produces 2 electrons, while the reduction of silver consumes only 1 electron. We can multiply the reduction half-reaction by 2 to balance the electrons:

\[
2\text{Ag}^+ + 2e^- \rightarrow 2\text{Ag}
\]

### Step 3: Combine the half-reactions

Now we can combine the balanced half-reactions:

1. Oxidation:
\[
\text{Zn} \rightarrow \text{Zn}^{2+} + 2e^-
\]

2. Reduction (doubled):
\[
2\text{Ag}^+ + 2e^- \rightarrow 2\text{Ag}
\]

Adding the half-reactions:

\[
\text{Zn} + 2\text{Ag}^+ \rightarrow \text{Zn}^{2+} + 2\text{Ag}
\]

### Final balanced equation:

The balanced overall equation for the reaction is:

\[
\text{Zn} + 2\text{Ag}^+ \rightarrow \text{Zn}^{2+} + 2\text{Ag}
\]

This equation ensures both mass and charge are balanced.