Name the following substance :
A yellow non-metal formed when hydrogen sulphide gas is passed through concentrated acid.

Explanation

To solve the question, we need to identify the yellow non-metal that is formed when hydrogen sulphide gas (H2S) is passed through concentrated acid, specifically concentrated sulfuric acid (H2SO4).

### Step-by-Step Solution:

1. **Identify the Reactants**:
- The reactants in this scenario are hydrogen sulphide (H2S) and concentrated sulfuric acid (H2SO4).

2. **Write the Chemical Reaction**:
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