Assertion : A mixture of camphor and ammonium chloride cannot be separated by sublimation.
Reason : Camphor on heating sublimes, ammonium chloride does not.

Options

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

Explanation

To solve the question regarding the assertion and reason about the mixture of camphor and ammonium chloride, we can break it down step by step.

### Step 1: Understanding the Assertion
The assertion states that a mixture of camphor and ammonium chloride cannot be separated by sublimation. To evaluate this, we need to consider what sublimation is and how it applies to both substances.

**Hint:** Recall the definition of sublimation and think about the properties of camphor and ammonium chloride.

### Step 2: Understanding Sublimation
Sublimation is the process where a solid changes directly into a gas without passing through the liquid phase. Both camphor and ammonium chloride are known to sublime under certain conditions.

**Hint:** Consider the physical states of both substances when heated.

### Step 3: Evaluating the Reason
The reason given states that camphor sublimes when heated, while ammonium chloride does not. This is incorrect because ammonium chloride also sublimes, although it may do so at a different temperature compared to camphor.

**Hint:** Think about the sublimation temperatures of both substances and whether ammonium chloride can sublime.

### Step 4: Conclusion
Since both substances can sublime, they cannot be separated by sublimation. Therefore, the assertion is true. However, the reason provided is false because it incorrectly states that ammonium chloride does not sublime.

**Final Answer:** The assertion is true, but the reason is false.

### Summary of Steps:
1. Understand the assertion about the separation of the mixture.
2. Define sublimation and its relevance to the substances in question.
3. Analyze the reason provided and its accuracy regarding ammonium chloride.
4. Conclude the truth of the assertion and the reason.