Acetone `overset( HCN) ( rarr) ( A) overset( H_(3) O^(+))(rarr) ( B ) `. In the above sequence of reaction A and B are `:`

Options

A. `( CH_(3))_(2) C( OH ) CN, ( CH_(3))_(2)C( OH ) COOH`
B. `( CH_(3))_(2)C(OH) CN, ( CH_(3))_(2)C ( OH)_(2)`
C. `( CH_(3))_(2)C(OH)CN,(CH_(3))_(2)CHCOOH`
D. `(CH_(3))_(2)C(OH)CN, ( CH_(3))_(2)C=O`

Answer

To solve the problem, we need to identify the products A and B formed from the reaction of acetone with HCN followed by H3O+. Let's break this down step by step.

### Step 1: Identify the structure of acetone
Acetone is a ketone with the formula \( \text{CH}_3\text{COCH}_3 \). Its structure can be represented as follows:

```
O
||
CH3-C-CH3
```

### Step 2: Reaction of acetone with HCN
When acetone reacts with HCN (hydrogen cyanide), a nucleophilic addition reaction occurs. The cyanide ion (CN⁻) attacks the carbonyl carbon (C=O) of acetone, leading to the formation of a cyanohydrin. The product A can be represented as:

```
OH
|
CH3-C-CH3
|
CN
```

This product is known as 2-hydroxy-2-methylpropanenitrile.

### Step 3: Reaction of product A with H3O+
When we add H3O⁺ (acidic medium) to the cyanohydrin, the nitrile group (CN) undergoes hydrolysis to form a carboxylic acid. The hydroxyl group (OH) remains, and the nitrile group is converted to a carboxylic acid group (COOH). The final product B can be represented as:

```
OH
|
CH3-C-CH3
|
COOH
```

This product is known as 2-hydroxy-2-methylpropanoic acid.

### Conclusion
Thus, the products A and B are:
- A: 2-hydroxy-2-methylpropanenitrile (CH3)2C(OH)CN
- B: 2-hydroxy-2-methylpropanoic acid (CH3)2C(OH)COOH

### Final Answer
A is 2-hydroxy-2-methylpropanenitrile, and B is 2-hydroxy-2-methylpropanoic acid.

---