Ten millilitre ofa mixture of methane, ethylene, and carbon dioxide was exploded with excess of air: After the explosion, there was contraction of 17 ml and after treatment with `KOH`, there was a further contraction of 14 ml. What was the composition of the mixture?

Explanation

To solve the problem of determining the composition of the gas mixture of methane (CH₄), ethylene (C₂H₄), and carbon dioxide (CO₂) after an explosion with excess air, we can follow these steps:

### Step 1: Understand the Contraction Volumes
After the explosion, there was a contraction of 17 ml. This contraction is primarily due to the formation of water vapor from the combustion of methane and ethylene. The second contraction of 14 ml after treatment with KOH indicates the absorption of CO₂, as KOH reacts with CO₂ to form potassium carbonate.

### Step 2: Identify the Reactions
1. **Combustion of Methane**:
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