`underset(H_(2)SO_(4))overset(K_(2)Cr_(2)O_(7))to (CH_(3))_(2)C=Ooverset(O)toCH_(3) COOH` , Here [A] is :

Options

A. Isopropyl alcohol
B. Ethyl alcohol
C. Tert butyl alcohol
D. Propyl alcohol

Answer

To determine the compound A in the given reaction sequence, we can follow these steps:

### Step 1: Identify the final product
The final product given is acetic acid (CH₃COOH). This indicates that the compound A must be an alcohol that can be oxidized to form a ketone, which can then be further oxidized to yield acetic acid.

### Step 2: Understand the oxidation process
The reaction involves the use of K₂Cr₂O₇ in the presence of H₂SO₄, which is a strong oxidizing agent. When a secondary alcohol is oxidized, it forms a ketone. If the ketone undergoes further oxidation, it can produce carboxylic acids.

### Step 3: Determine the structure of the ketone
The ketone produced in the reaction is (CH₃)₂C=O, which is acetone. This indicates that the alcohol A must be a secondary alcohol that, upon oxidation, gives acetone.

### Step 4: Identify the secondary alcohol
The only secondary alcohol that can be oxidized to form acetone is isopropyl alcohol (2-propanol), which has the structure:
```
CH₃
|
CH₃ - C - OH
```
This structure confirms that it is a secondary alcohol because the carbon bearing the hydroxyl group (OH) is attached to two other carbon atoms.

### Step 5: Confirm the oxidation sequence
1. **Oxidation of isopropyl alcohol (A)**:
- Isopropyl alcohol (A) → Acetone (CH₃)₂C=O (ketone)
2. **Further oxidation of acetone**:
- Acetone → Acetic acid (CH₃COOH)

### Conclusion
Thus, the compound A is isopropyl alcohol, which can be represented as:
**A = Isopropyl alcohol (2-propanol)**

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