Question

A mixture of hydrogen and oxygen at one bar pressure contains 20% by weight of hydrogen. Partial pressure of hydrogen will be

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

Answer 1

Answer: (D)

0.8 bar

Answer 2

Weight of H2 = 20 g in 100 g mixture ; Weight of O2 = 80 g

$\therefore$ Moles of H2 $= \frac { 20 } { 2 } = 10$;

$= \frac { 80 } { 32 } = \frac { 5 } { 2 }$

$= 10 + \frac { 5 } { 2 } = \frac { 25 } { 2 }$

$\therefore$ = PT x mole fraction of H2