A certain quantity of a gas occupies 100 mL when collected over water at `15^(@)C` and 750 mm pressure. It occupies `91.9 mL` in dry state at NTP. Find the aqueous vapour pressure at `15^(@)C`.

Explanation

To solve the problem step by step, we will use the ideal gas law and the relationship between the pressures involved.

### Step 1: Understand the given data
We have the following information:
- Volume of gas collected over water (V1) = 100 mL
- Pressure when collected over water (P_total) = 750 mmHg
- Temperature when collected (T1) = 15°C = 288 K (conversion: 15 + 273)
- Volume of gas in dry state at NTP (V2) = 91.9 mL
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