`90 mL` of oxygen is required for complete combustion of unsaturated `20mL` gaseous hydrocarbon, hydrocarbon is ?

Explanation

To determine the unsaturated hydrocarbon based on the given information, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Problem**: We are given that 90 mL of oxygen is required for the complete combustion of 20 mL of an unsaturated hydrocarbon. We need to identify the hydrocarbon.

2. **Identify the Type of Hydrocarbon**: Unsaturated hydrocarbons can be alkenes or alkynes. Alkenes have the general formula \( C_nH_{2n} \) and alkynes have the general formula \( C_nH_{2n-2} \).

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