Assertion (A) Coagulation power of `Al^(3+)` is more than `Na^(+)`.
Reason (R) Greater the valency of the flocculating ion added, greater is its power to cause precipitation (Hardy-Schulze rule) .
(a)Assertion and reason both are correct and the reason is correct explanation of assertion.
(b)Assertion and reason both are correct but reason does not explain assertion.
(c)Assertion is correct, but reason is incorrect.
(d)Assertion is incorrect, but reason is correct.

Options

A. Assertion and reason both are correct and the reason is correct explanation of assertion.
B. Assertion and reason both are correct but reason does not explain assertion.
C. Assertion is correct, but reason is incorrect.
D. Assertion is incorrect, but reason is correct.

Explanation

To solve the question, we need to analyze both the assertion and the reason provided.

### Step 1: Understand the Assertion
The assertion states that the coagulation power of \( \text{Al}^{3+} \) is more than \( \text{Na}^{+} \). Coagulation power refers to the ability of an ion to cause the precipitation of colloidal particles.

### Step 2: Understand the Reason
The reason states that according to the Hardy-Schulze rule, the greater the valency of the flocculating ion, the greater its power to cause precipitation. This means that ions with higher charges are more effective at coagulating colloidal solutions.

### Step 3: Analyze the Ions
- **Aluminum Ion (\( \text{Al}^{3+} \))**: This ion has a charge of +3.
- **Sodium Ion (\( \text{Na}^{+} \))**: This ion has a charge of +1.

### Step 4: Compare Coagulation Power
According to the Hardy-Schulze rule:
- The coagulating power is directly proportional to the charge (valency) of the ion.
- Since \( \text{Al}^{3+} \) has a higher charge than \( \text{Na}^{+} \), it will have a greater coagulating power.

### Step 5: Conclusion
Both the assertion and the reason are correct. The reason correctly explains why the assertion is true: the greater valency of \( \text{Al}^{3+} \) compared to \( \text{Na}^{+} \) leads to a higher coagulation power.

### Final Answer
The correct option is:
**(a) Assertion and reason both are correct and the reason is correct explanation of assertion.**

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