Distinction between pairs of compounds
Ethylene and Acetylene.

Explanation

To distinguish between ethylene (C2H4) and acetylene (C2H2), we can perform a couple of chemical tests based on their structural differences and reactivity. Here’s a step-by-step explanation of the distinctions:

### Step 1: Identify the Structures
- **Ethylene**: The molecular formula is C2H4, and it has a double bond between the two carbon atoms (CH2=CH2).
- **Acetylene**: The molecular formula is C2H2, and it has a triple bond between the two carbon atoms (CH≡CH).

### Step 2: React with Sodium Hydroxide (NaOH)
- **Ethylene**: When ethylene is treated with NaOH, no reaction occurs because it does not have any acidic hydrogen atoms.
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