Which one of the following compounds would not be easily oxidised by `K_(2) Cr_(2) O_(7) "in dil" H_(2) SO_(4)` ?

Options

A. `CH_(3) OH`
B. `(CH_(3))_(3)COH`
C. `CH_(3)CH_(2)OH`
D. `CH_(3)CHO`

Answer

To determine which compound would not be easily oxidized by potassium dichromate (K₂Cr₂O₇) in dilute sulfuric acid (H₂SO₄), we need to analyze the oxidation behavior of different types of alcohols and aldehydes.

### Step-by-step Solution:

1. **Understanding the Oxidation Process**:
- Potassium dichromate in acidic medium is a strong oxidizing agent. It can oxidize primary and secondary alcohols to aldehydes and ketones, respectively, and further oxidize aldehydes to carboxylic acids.

2. **Identifying the Types of Compounds**:
- **Primary Alcohols**: These can be oxidized to aldehydes and then to carboxylic acids.
- **Secondary Alcohols**: These can be oxidized to ketones.
- **Tertiary Alcohols**: These do not oxidize easily because they lack a hydrogen atom on the carbon bearing the hydroxyl group, making it difficult to form a carbonyl compound.
- **Aldehydes**: These can be oxidized to carboxylic acids.

3. **Analyzing Each Option**:
- **Option A**: Primary alcohol - Easily oxidized to aldehyde and then to acid.
- **Option B**: Tertiary alcohol - Not easily oxidized due to the absence of a hydrogen atom on the carbon with the hydroxyl group.
- **Option C**: Primary alcohol - Easily oxidized to aldehyde and then to acid.
- **Option D**: Aldehyde - Easily oxidized to carboxylic acid.

4. **Conclusion**:
- The compound that would not be easily oxidized by K₂Cr₂O₇ in dilute H₂SO₄ is **Option B**, which is a tertiary alcohol.

### Final Answer:
**Option B (Tertiary alcohol) would not be easily oxidized by K₂Cr₂O₇ in dilute H₂SO₄.**