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 determine which statements regarding oxidation and reduction are correct, we will follow these steps:

### Step 1: Identify the Reactants and Products
The reaction given 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: Assign Oxidation States
- **Formaldehyde (HCHO)**:
- Carbon (C) in HCHO has an oxidation state of +1.
- **Silver complex \([\text{Ag(NH}_3)_2]^+\)**:
- Silver (Ag) in this complex has an oxidation state of +1.
- **Formate ion (HCOO⁻)**:
- Carbon (C) in HCOO⁻ has an oxidation state of +1.
- **Silver (Ag)**:
- In elemental form, Ag has an oxidation state of 0.

### Step 3: Determine Changes in Oxidation States
- **HCHO to HCOO⁻**:
- The oxidation state of carbon does not change (remains +1), but it loses a hydrogen atom and gains an oxygen atom. This indicates that HCHO is oxidized.
- **Ag from \([\text{Ag(NH}_3)_2]^+\) to Ag**:
- The oxidation state of Ag changes from +1 to 0, indicating that Ag is reduced.

### Step 4: Identify Oxidation and Reduction
- **Oxidation**:
- HCHO is oxidized as it loses hydrogen and gains oxygen.
- **Reduction**:
- Ag is reduced as it goes from +1 to 0.

### Step 5: Conclusion
Based on the analysis:
- HCHO is oxidized.
- Ag is reduced.

Thus, the correct statement regarding oxidation and reduction in this reaction is that HCHO is oxidized and Ag is reduced.

### Final Answer
The correct statement regarding oxidation and reduction is:
- **HCHO is oxidized and Ag is reduced.**