(a) Explain the mechanism of a nucleophilic attack on the carbonyl group of an aldehyde or a ketone.
(b) An organic commpound (A) (molecular formula `C_(8)H_(16)O_(2)`) was hydrlysed with dilute sulphuric acid to give a carboxylic acid (B) and an alcohol (C). Oxidatin of (C) with chromic acid also produced (B). On dehydratin (C) gives but-1-ene. Write the equations for the reactions involved.

Explanation

### Step-by-Step Solution:

**(a) Mechanism of Nucleophilic Attack on the Carbonyl Group:**

1. **Structure of Carbonyl Group:**
- A carbonyl group (C=O) can be found in aldehydes and ketones. In aldehydes, one of the substituents on the carbonyl carbon is a hydrogen atom, while in ketones, both substituents are alkyl groups.
- The carbon atom in the carbonyl group is sp² hybridized, leading to a planar structure.

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