An oxygen cylinder of volume 30 litre has 18.20 moles of oxygen. After some oxygen is withdrawn from the cylinder, its gauge pressure drops to 11 atmospheric pressure at temperature 27°C. The mass of the oxygen withdrawn from the cylinder is nearly equal to:
[Given, R = \(R = \frac{100}{12} \) J mol⁻¹ K⁻¹, and molecular mass of O₂ = 32, 1 atm pressure = 1.01 × 10⁵ N/m²]

Question

Question

This question was previously asked in

NEET 2025 Official Paper (Held On: 04 May, 2025)

Answer 1

Correct option is: (3) 0.116 kg

Number of moles left

n = PV / RT = (12 × 1.01 × 10⁵ N/m² × 30 × 10⁻³ m³) / ((100/12) × 300)

n = (12 × 1.01 × 12) / 10 = 14.54 moles

Moles removed = 18.2 − 14.54

= 3.656 moles

Mass removed = 3.656 × 32 = 116.99 g = 0.116 kg