A : Aldehydes and ketones undergo nucleophilic addition reaction.
R : Aldehydes and ketones contain carbonyl group.

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 analyze the statements given in the question, we need to evaluate both the assertion (A) and the reason (R).

### Step 1: Understanding the Assertion (A)
The assertion states that "Aldehydes and ketones undergo nucleophilic addition reactions."

- Aldehydes and ketones contain a carbonyl group (C=O).
- In these compounds, the carbon atom of the carbonyl group has a partial positive charge due to the electronegativity difference between carbon and oxygen.
- Nucleophiles, which are species with a negative charge or a lone pair of electrons, are attracted to this positively charged carbon atom.
- Therefore, nucleophiles can attack the carbonyl carbon, leading to nucleophilic addition reactions.

**Conclusion for Step 1:** The assertion is correct.

### Step 2: Understanding the Reason (R)
The reason states that "Aldehydes and ketones contain a carbonyl group."

- The carbonyl group (C=O) is indeed present in both aldehydes and ketones.
- Aldehydes have the general structure RCHO, while ketones have the structure RCOR', where R and R' can be the same or different.
- The presence of the carbonyl group is what makes these compounds susceptible to nucleophilic attack.

**Conclusion for Step 2:** The reason is also correct.

### Step 3: Relationship Between Assertion and Reason
Now, we need to determine if the reason correctly explains the assertion.

- The assertion is that aldehydes and ketones undergo nucleophilic addition reactions, and the reason is that they contain a carbonyl group.
- The presence of the carbonyl group is indeed the reason why these compounds undergo nucleophilic addition reactions, as it creates a site of electrophilicity (the positively charged carbon) that nucleophiles can attack.

### Final Conclusion
Both the assertion and the reason are correct, and the reason correctly explains the assertion.

### Answer:
Both A and R are correct, and R is the correct explanation for A.

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