Consider the following reaction : `HCHO+2[Ag(NH_(3))_(2)]^(+)+3OH^(-)rarr2Ag+HCO O^(-)+4NH_(3)+2H_(2)O`
Which of the following statements regarding oxidation and reduction is correct?

Options

A. HCHO is oxidised to `HCO O^(-)` and `[Ag(NH_(3))_(2)]^(+)` is reduced to Ag.
B. HCHO is reduced to `ddHCO O^(-)` and `[Ag(NH_(3))_(2)]^(+)` is oxidised to Ag.
C. `[Ag(NH_(3))_(2)]^(+)` is reduced to Ag while `OH^(-)` is oxidised to `HC O O^(-)`
D. `[Ag(NH_(3))_(2)]^(+)` is oxidised to `NH_(3)` while HCHO is reduced to `H_(2)O`.

Explanation

To analyze the given reaction and identify the correct statements regarding oxidation and reduction, we will follow these steps:

### Step 1: Write down the reaction
The reaction provided is:
\[ \text{HCHO} + 2[\text{Ag(NH}_3)_2]^+ + 3\text{OH}^- \rightarrow 2\text{Ag} + \text{HCOO}^- + 4\text{NH}_3 + 2\text{H}_2\text{O} \]

### Step 2: Identify the oxidation states
- **Formaldehyde (HCHO)**: The carbon in formaldehyde has an oxidation state of +1.
- **Formate ion (HCOO⁻)**: The carbon in the formate ion has an oxidation state of +1.
- **Silver ion (Ag⁺)**: The oxidation state of silver in \([\text{Ag(NH}_3)_2]^+\) is +1.
- **Silver (Ag)**: The oxidation state of elemental silver is 0.

### Step 3: Determine oxidation and reduction
- **Oxidation**: A substance is oxidized if it loses electrons or increases its oxidation state. In this case, HCHO is being oxidized to HCOO⁻, but the oxidation state of carbon remains +1. Therefore, there is no change in oxidation state for carbon, indicating that the aldehyde is being converted to a carboxylate ion.

- **Reduction**: A substance is reduced if it gains electrons or decreases its oxidation state. Here, \([\text{Ag(NH}_3)_2]^+\) is reduced to Ag (0), as the oxidation state of silver decreases from +1 to 0.

### Step 4: Conclusion
From the analysis:
- HCHO does not change its oxidation state, but it is part of the overall reaction where it is involved in the conversion to HCOO⁻.
- \([\text{Ag(NH}_3)_2]^+\) is reduced to Ag (0).

Thus, the correct statements regarding oxidation and reduction in this reaction are:
- HCHO is oxidized to HCOO⁻ (even though the oxidation state does not change, it is considered an oxidation process in this context).
- \([\text{Ag(NH}_3)_2]^+\) is reduced to Ag (0).

### Final Answer
The correct statements regarding oxidation and reduction are:
- HCHO is oxidized to HCOO⁻.
- \([\text{Ag(NH}_3)_2]^+\) is reduced to Ag (0).