Question

Equal weights $C_2{H}_6$ and hydrogen are mixed in an empty container at $0^{o}C$. The fraction of total pressure exerted by hydrogen is-

• A. $1:2$
• B. $1:1$
• C. $1:16$
• D. $15:16$

Answer 1

The correct option is D $15:16$

Consider x gm be the weight of $C_2{H}_6$ and hydrogen.
No. of moles of hydrogen = x/2
No. of moles of $C_2{H}_6$ = x/30
Mole fraction of hydrogen =( x/2)/(x/2+x/30) = 15/16
The pressure exerted by hydrogen = mole fraction of hydrogen * total pressure
= 15/16 * 1 = 15/16