A: Urea is a diamide of carbonic acid.
R: Aqueous solution of urea is neutral.

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (1).
B. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark (2)
C. If Assertion is true statement but Reason is false, then mark (3)
D. If both Assertion and Reason are false statements, then mark (4)

Answer

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

### Step 1: Analyze the Assertion
- **Assertion**: Urea is a diamide of carbonic acid.
- **Explanation**: Carbonic acid (H2CO3) has the structure of a carbon atom double bonded to an oxygen atom (C=O) and two hydroxyl groups (OH). When we refer to urea, its chemical formula is (NH2)2CO, which can be derived from carbonic acid by replacing the hydroxyl groups (OH) with amine groups (NH2). Therefore, urea can indeed be considered as the diamide of carbonic acid.

### Step 2: Analyze the Reason
- **Reason**: The aqueous solution of urea is neutral.
- **Explanation**: When urea is dissolved in water, it does not release hydrogen ions (H+) or hydroxide ions (OH-), which means it does not exhibit acidic or basic properties. Thus, the solution remains neutral.

### Step 3: Conclusion
- Both the assertion and the reason are true. However, the reason provided does not serve as a correct explanation for the assertion because the neutrality of urea in solution does not directly explain why it is classified as a diamide of carbonic acid.

### Final Answer
- The assertion is true, and the reason is true, but the reason is not the correct explanation for the assertion.