Question

Equal masses of methane and oxygen are mixed in an empty container at 25⁰C. The fraction of the total pressure exerted by oxygen is

• A. 1/3
• B. 1/2
• C. 2/3
• D. $\frac { 1 } { 3 }$×$\frac { 273 } { 298 }$

Answer 1

Answer: (A)

1/3

Answer 2

Let the mass of methane and oxygen be m gm. Mole fraction of oxygen xo2

Let the total pressure be P.

$\therefore$ Partial pressure of O2, Po2 = P× xo2

P ×$\frac { 1 } { 3 }$ P.