Compound that will give positive Lassaigne's test for both nitrogen and halogen is:

Options

A. `NH_(2)OH.HCl`
B. `CH_(3)NH_(2)HCl`
C. `NH_4Cl`
D. `N_(2)H_(4)HCl`

Answer

To solve the problem of identifying the compound that will give a positive Lassaigne's test for both nitrogen and halogen, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Lassaigne's Test**:
- Lassaigne's test is used to detect the presence of nitrogen and halogens in organic compounds. For a compound to give a positive test for both nitrogen and halogen, it must contain carbon (C), nitrogen (N), and a halogen (X, such as Cl, Br, or I).

2. **Identify the Requirements**:
- The compound must contain:
- Carbon (C)
- Nitrogen (N)
- A halogen (X)

3. **Evaluate Given Options**:
- Let's assume we have several compounds to evaluate. We need to check each compound for the presence of C, N, and X.
- For each compound:
- If it contains nitrogen and halogen but lacks carbon, it will not give a positive test.
- If it contains carbon, nitrogen, and a halogen, it will give a positive test.

4. **Analyze Each Option**:
- **Option 1**: Contains nitrogen and halogen but no carbon. **(Negative Test)**
- **Option 2**: Contains carbon, nitrogen, and halogen. **(Positive Test)**
- **Option 3**: Contains nitrogen and halogen but no carbon. **(Negative Test)**
- **Option 4**: Contains nitrogen and halogen but no carbon. **(Negative Test)**

5. **Conclusion**:
- The only compound that meets all the criteria (contains carbon, nitrogen, and halogen) is **Option 2**. Therefore, this compound will give a positive Lassaigne's test for both nitrogen and halogen.

### Final Answer:
The compound that will give a positive Lassaigne's test for both nitrogen and halogen is **Option 2**.