Question

$16gm$ of $O_2$ was filled in a container of capacity $8.21$ lit. at $300K$. Calculate
(i) Pressure exerted by $O_2$
(ii) Partial pressure of $O_2$ and $O_3$ if $50$% of oxygen is converted into ozone at same temperature
(iii) Total pressure exerted by gases if $50$% of oxygen is converted into ozone ($O_3$) at temperature $50K$

Answer 1

i) $PV=nRT$

$\Rightarrow P=\frac{\left(16/32\right)\times 0.0821\times 300}{8.21}=1.5$atm

ii) ${3O}_2\to 2O_3$

$\therefore 0.25$ moles of $O_2$ is converted to $\frac{0.25\times 2}{3}$ moles i.e., $0.167$ moles of $O_3$

iii) At $50K,p_{O_2}=\frac{n_{O_2}RT}{V}$ and $P_{O_3}=\frac{n_{O_3}RT}{V}$

$P_{total}=p_{O_2}+p_{O_3}=(n_{O_2}+n_{O_3})RT/V$

$=\frac{(0.25+0.167)\times 0.0821\times 50}{8.21}=0.2085$ atm.