Question

Equal weights of ethane and hydrogen are mixed in an empty container at $25^\circ$ C. The fraction of the total pressure exerted by hydrogen is

• A. 1:02
• B. 1:01
• C. 1:16
• D. 15:16

Answer 1

Answer: (D)

15:16

Answer 2

Let x g of each gas is mixed.
Mole of ethane$=\frac{x}{30}$
$\, \, \, \, \, \, \, \, Mole of hydrogen =\frac{x}{2}$
Mole fraction of hydrogen$=\frac{\frac{x}{2}}{\frac{x}{2}+\frac{x}{30}}=\frac{15}{16}$
$\Rightarrow \, \, \, \frac{Partial\, pressure\, of\, H_2}{Total\, pressure}=$Mole fraction of hydrogen