Assertion(A): The mass of nickle catalyst recovered after being used in the hydroenation of an oil is less than the mass of nickle added to the reaction.
Reason(R): Catalyst take part in the reaction but the are recoveres in the end.

Options

A. If both (A) and (R) are correct, and (R) is the correct explanation of (A)
B. If both (A) and (R) are correct, but (R) is the correct explanation of (A).
C. If (A) is correct, but (R) is incorrect.
D. If (A) is incorrect, but (R) is correct. S

Answer

To analyze the given assertion and reason, let's break it down step by step:

### Step 1: Understanding the Assertion
The assertion states that "the mass of nickel catalyst recovered after being used in the hydrogenation of an oil is less than the mass of nickel added to the reaction."

### Step 2: Understanding the Role of a Catalyst
A catalyst is defined as a substance that increases the rate of a chemical reaction by lowering the activation energy required for the reaction to occur. Importantly, a catalyst is not consumed in the reaction, meaning that its mass and chemical composition remain unchanged after the reaction.

### Step 3: Evaluating the Assertion
Since a catalyst is not consumed in the reaction, the mass of the nickel catalyst should remain the same before and after the reaction. Therefore, the assertion that the mass of nickel recovered is less than the mass of nickel added is incorrect.

### Step 4: Understanding the Reason
The reason states that "catalysts take part in the reaction but are recovered in the end." This statement is partially true. While catalysts do facilitate the reaction, they do not undergo any permanent change and can be recovered in their original form after the reaction is complete.

### Step 5: Conclusion
- The assertion is **false** because the mass of the catalyst does not change.
- The reason is **true** in that catalysts facilitate the reaction but do not get consumed.

Thus, the correct answer is that the assertion is incorrect while the reason is correct.

### Final Answer
The assertion is false, and the reason is true. Therefore, the correct option is D.

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