Consider the following reaction:
`X(aq.) overset(K_(4)[Fe(CN)_(6)])to ` Chocolate brown ppt.
`X(aq.) overset(AgNO_(3))to`White ppt. (insoluble in dil. `HNO_(3)`)
Then 'X' will be:

Options

A. `ZnSO_(4)`
B. `CuCl_(2)`
C. `FeSO_(4)`
D. `FeCl_(3)`

Explanation

To solve the problem, we need to analyze the reactions given and identify the compound 'X' based on the observations provided.

### Step-by-Step Solution:

1. **Understanding the First Reaction**:
- The first reaction states that `X(aq)` reacts with `K4[Fe(CN)6]` to produce a chocolate brown precipitate.
- Potassium ferrocyanide (`K4[Fe(CN)6]`) typically reacts with certain metal ions to form colored precipitates. The chocolate brown precipitate suggests the presence of copper ions (Cu²⁺), which form a brown precipitate with ferrocyanide.

2. **Understanding the Second Reaction**:
- The second reaction states that `X(aq)` reacts with `AgNO3` to produce a white precipitate that is insoluble in dilute `HNO3`.
- Silver nitrate (`AgNO3`) reacts with halides (like chloride ions) to form white precipitates. The fact that the precipitate is insoluble in dilute nitric acid indicates that the anion in 'X' is likely a chloride ion (Cl⁻).

3. **Analyzing the Options**:
- The options given are:
1. Zinc Sulphate (ZnSO4)
2. Copper Chloride (CuCl2)
3. Iron Sulphate (FeSO4)
4. Iron Chloride (FeCl3)
- From the second reaction, we can eliminate Zinc Sulphate and Iron Sulphate, as they do not produce a white precipitate with AgNO3.

4. **Identifying the Suitable Compound**:
- The remaining options are Copper Chloride (CuCl2) and Iron Chloride (FeCl3).
- Copper Chloride (CuCl2) would produce a chocolate brown precipitate with potassium ferrocyanide due to the presence of Cu²⁺ ions.
- Iron Chloride (FeCl3) does not produce a chocolate brown precipitate with potassium ferrocyanide; instead, it would produce a different colored precipitate.

5. **Conclusion**:
- Based on the observations and the reactions analyzed, the compound 'X' must be **Copper Chloride (CuCl2)**, as it meets both criteria of forming a chocolate brown precipitate with potassium ferrocyanide and a white precipitate with silver nitrate.

### Final Answer:
**X = Copper Chloride (CuCl2)**