(i) Write structural formula of the compound formed when one mole of ethyne reacts with one mole of hydrogen gas.
(ii)Name the catalyst used in the above reaction.
(iii) Write temperature at which the reaction mentioned in (a) occurs.
(iv) Name the reaction.

Explanation

Let's break down the solution to the question step by step.

### Step 1: Write the structural formula of the compound formed when one mole of ethyne reacts with one mole of hydrogen gas.

**Solution:**
Ethyne (C2H2) is an alkyne with a triple bond between the two carbon atoms. When ethyne reacts with hydrogen gas (H2), it undergoes hydrogenation, which means hydrogen is added to the molecule.

The reaction can be represented as:
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