Question

A mixture of hydrogen and oxygen at one bar pressure contains 20% by weight of hydrogen. Find the partial pressure of hydrogen.

• A. 0.2 bar
• B. 0.4 bar
• C. 0.6 bar
• D. 0.8 bar

Answer 1

The correct option is D

0.8 bar

Weight of $H_2$ = 20 g in 100 g mixture ; Weight of $O_2$ = 80 gm

$\therefore Molesof{H}_2=\frac{20}{2}\Rightarrow 10$

$\therefore Molesof{O}_2=\frac{80}{32}\Rightarrow \frac{5}{2}$

$\therefore Totalmoles=10+\frac{5}{2}\Rightarrow \frac{25}{2}$

$P_{H_2}=P_T\times molefractionof{H}_2=1\times \frac{10}{\frac{25}{2}}\Rightarrow 0.8bar.$