Describe a method to distinguish ethane, ethene and ethyne.

Explanation

To distinguish between ethane (C2H6), ethene (C2H4), and ethyne (C2H2), we can use two different reagents: Baeyer’s reagent and ammoniacal cuprous chloride. Here’s a step-by-step method:

### Step 1: Test with Baeyer’s Reagent
1. **Prepare Baeyer’s Reagent**: This is a cold dilute alkaline solution of potassium permanganate (KMnO4).
2. **Add the Hydrocarbon**: Take a small amount of each hydrocarbon (ethane, ethene, and ethyne) and add it separately to the Baeyer’s reagent.
3. **Observe the Reaction**:
- **Ethane (C2H6)**: No reaction occurs. The purple color of the reagent remains unchanged.
- **Ethene (C2H4)**: The purple color of the reagent will decolorize, indicating a reaction due to the presence of a double bond (unsaturation).
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