Assertion: `Al(OH)_(3)` is amphoteric in nature. Reason: It cannot be used as an antacid.

Options

A. If both (A) and (R) are true and (R) is the correct explanation of (A)
B. if both (A) and (R) are true but (R) is not correct explanation of (A)
C. If (A) is true but (R) is false
D. If (A) is false but (R) is false

Explanation

To analyze the given assertion and reason, we will break it down step by step.

### Step 1: Understanding the Assertion
The assertion states that **Al(OH)₃ (aluminum hydroxide) is amphoteric in nature**.

**Explanation**:
- An amphoteric substance is one that can react with both acids and bases.
- Aluminum hydroxide can react with acids to form salts and water, and it can also react with bases to form complex ions.

### Step 2: Confirming the Assertion
To confirm that Al(OH)₃ is amphoteric, we can look at its reactions:

1. **Reaction with Acid**:
- When aluminum hydroxide reacts with hydrochloric acid (HCl):
\[ \text{Al(OH)}_3 + 3\text{HCl} \rightarrow \text{AlCl}_3 + 3\text{H}_2\text{O} \]
This shows that it can react with an acid.

2. **Reaction with Base**:
- When aluminum hydroxide reacts with sodium hydroxide (NaOH):
\[ \text{Al(OH)}_3 + \text{OH}^- \rightarrow \text{[Al(OH)}_4]^- \]
This shows that it can also react with a base.

Thus, the assertion that Al(OH)₃ is amphoteric is **correct**.

### Step 3: Understanding the Reason
The reason states that **Al(OH)₃ cannot be used as an antacid**.

**Explanation**:
- Antacids are typically weak bases that neutralize stomach acid (HCl) to relieve heartburn and indigestion.
- Aluminum hydroxide is indeed used as an antacid because it can neutralize excess stomach acid.

### Step 4: Confirming the Reason
To confirm the reason:
- Aluminum hydroxide (Al(OH)₃) is commonly used in various antacid formulations. It reacts with stomach acid to form aluminum chloride and water, thereby alleviating acidity.

Since aluminum hydroxide is used as an antacid, the reason given is **incorrect**.

### Conclusion
- **Assertion**: Correct (Al(OH)₃ is amphoteric)
- **Reason**: Incorrect (Al(OH)₃ can be used as an antacid)

### Final Answer
The correct option is that the assertion is true, but the reason is false.

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