Question

At S.T.P a container has 1 mole of $H_2$, $2$ mole $Ne$, $3$ mole $O_2$ and $4$ mole $N_2$. Without changing total pressure if $2$ mole of $O_2$ is removed, the partial pressure of $O_2$ will be decreased by:

• A. $26\%$
• B. $40\%$
• C. $58.33\%$
• D. $66.66\%$

Answer 1

The correct option is C $58.33\%$

$P_{O_2}=\frac{3}{10}\times P_T$

After removing 2 mole of $O_2$,

$P_{O_2}^{\prime }=\frac{1}{8}\times P_T$

Decrease in partial pressure of $O_2=\frac{\frac{3P_T}{10}-\frac{P_T}{8}}{\frac{3P_T}{10}}\times 100$

$=58.33\%$