Statement-I : `Li_(2)SO_(4)` do not form double salt like alum.
Statement-II : `Li` reacts with `NH_(3)` gas to form `LiNH_(2)`

Options

A. If both assertion and reason are true and the reason is the correct explanation of assertion
B. If both assertion and reason are true and the reason is not the correct explanation of assertion
C. If assertion is false but reason is true
D. If assertion is true but the reason is false

Explanation

To analyze the given statements, we will break down each statement and evaluate their validity step by step.

### Step 1: Evaluate Statement-I
**Statement-I:** `Li_(2)SO_(4)` does not form double salts like alum.

**Explanation:**
- Double salts are formed when two different salts crystallize together in a specific ratio.
- Lithium sulfate (`Li2SO4`) does not form double salts due to the small size of the lithium ion (`Li+`).
- The small size leads to a high charge density, which makes it less likely to combine with other cations to form stable double salts.
- In contrast, alum is a double salt that typically involves larger cations (like potassium or ammonium) which can stabilize the structure.

**Conclusion for Statement-I:** True.

### Step 2: Evaluate Statement-II
**Statement-II:** `Li` reacts with `NH_(3)` gas to form `LiNH_(2)`.

**Explanation:**
- When lithium (`Li`) reacts with ammonia (`NH3`), the expected product is not lithium amide (`LiNH2`), but rather lithium imide (`Li2NH`).
- The reaction can be represented as:
\[ 2Li + NH3 \rightarrow Li2NH + H2 \]
- Therefore, the claim that lithium reacts with ammonia to form `LiNH2` is incorrect.

**Conclusion for Statement-II:** False.

### Final Conclusion:
- **Statement-I** is true: `Li_(2)SO_(4)` does not form double salts like alum.
- **Statement-II** is false: `Li` does not react with `NH_(3)` to form `LiNH_(2)` but rather `Li2NH`.

### Overall Result:
- The assertion (Statement-I) is true, while the reason (Statement-II) is false.

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