Pure hydrogen sulphide is stored in a tank of 100 litre capacity at 20ºC and 2 atm pressure. The mas — States of Matter and Gaseous State Chemistry Question

💡 Solution & Explanation

# Solution: Mass of Pure Hydrogen Sulphide **Step 1: Identify the given data** - Volume: $V = 100$ L - Temperature: $T = 20°C = 293$ K - Pressure: $P = 2$ atm - Molar mass of $H_2S$ = 2(1) + 32 = 34 g/mol **Step 2: Apply the ideal gas law** $$PV = nRT$$ where $R = 0.0821$ L·atm·mol⁻¹·K⁻¹ **Step 3: Calculate number of moles** $$n = \frac{PV}{RT} = \frac{2 \times 100}{0.0821 \times 293}$$ $$n = \frac{200}{24.055} \approx 8.315 \text{ mol}$$ **Step 4: Calculate mass** $$\text{Mass} = n \times M = 8.315 \times 34 \approx 283 \text{ g}$$ **Answer:** The mass of $H_2S$ stored is approximately **280–283 g** (or **0.28 kg**). This uses the ideal gas equation directly without needing to convert to molar volume, making it the most straightforward approach for non-standard conditions.