Question

Equal weights of methane and hydrogen are mixed in an empty container at 25°C. The fraction of the total pressure exerted by hydrogen is

(a) 1/2

(b) 8/9

(c) 1/9

(d) 16/17

Answer 1

Correct option (b) 8/9

Explanation:

Let the weight be w g.

Thus. moles of H₂ = w/2 and motes of CH₄ =  w/16

Total number of moles  = w/2 + w/16 = 9w/16

Partial pressure of H₂ =  total pressure x mole fraction of H₂

 Hence, the fraction of the total pressure exerted by H₂  = 8/9.