Question

A vessel contains 1 mole of O₂ gas (relative molar mass 32) at a temperature T. The pressure of the gas is P. An identical vessel containing 1 mole of He gas (relative molar mass 4) at a temperature 2T has pressure of.. 

(A) 8 P 

(B) (p/8) 

(C) 2 P 

(D) P

Answer 1

Correct option: (C) 2 P

Explanation:

PV = nRT

For both gases n = 1 mole

Also vessels are same i.e. V is constant hence 

P = {(nRT) / v}

P = constant × T

∴ P ∝ T

∴ (P₁ / P₂) = (T₁ / T₂)

Given: P₁ = P

T₁ = T

T₂ = 2T

Hence P₂ = {(P₁ T₂) / (T₁)} = {(P × 2T) / T} = 2P