i.(A)`underset(Delta)overset(NaOH)rarr(B)(g) overset(HCI)rarr` While fumes.
ii. After (B) is expelled completely, resultant alkline solution again gives gas (B) on heating with zine
iii.(A) `overset(Delta)rarr N_(2)O +H_(2)O`
Identify A

Options

A. `NH_(4)NO_(2)`
B. `NH_(4)NO_(3)`
C. `HCI`
D. `NaSO_(4)`

Explanation

To identify compound A from the given reactions, we can follow these steps:

### Step-by-Step Solution:

1. **Analyze the First Reaction:**
- The first reaction states that compound A reacts with sodium hydroxide (NaOH) to produce gas B.
- The reaction can be represented as:
\[ A + \text{NaOH} \rightarrow B \]

2. **Analyze the Second Reaction:**
- The second reaction indicates that gas B reacts with hydrochloric acid (HCl) to produce white fumes.
- The reaction can be represented as:
\[ B + \text{HCl} \rightarrow \text{White Fumes} \]
- The white fumes are typically indicative of ammonium chloride (NH4Cl), which is formed when ammonia (NH3) gas reacts with HCl.

3. **Analyze the Third Reaction:**
- The third reaction states that upon heating, compound A decomposes to produce dinitrogen oxide (N2O) and water (H2O).
- The reaction can be represented as:
\[ A \xrightarrow{\Delta} N_2O + H_2O \]
- This decomposition is characteristic of ammonium nitrate (NH4NO3).

4. **Identify Compound A:**
- Given the reactions and the products, we can deduce that compound A is likely ammonium nitrate (NH4NO3).
- Ammonium nitrate decomposes upon heating to produce dinitrogen oxide (N2O) and water (H2O).
- When ammonium nitrate reacts with NaOH, it produces sodium nitrate (NaNO3) and ammonia (NH3), which upon reaction with HCl produces the white fumes of ammonium chloride.

### Conclusion:
Thus, the compound A is identified as:
\[ \text{A} = \text{NH}_4\text{NO}_3 \text{ (Ammonium Nitrate)} \]

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