EXERCISES

Density of a gas is found to be $5.46\mathrm{}\mathrm{g}/{\mathrm{d}\mathrm{m}}^3$ at ${27}^{\mathrm{o}}\mathrm{C}$ at $2$ bar pressure. What will be its density at STP?

$34.05 \mathrm{m}\mathrm{L}$ of phosphorus vapour weighs $0.0625 \mathrm{g}$ at ${546}^{\mathrm{o}} \mathrm{C}$ and $0.1$ bar pressure. What is the molar mass of phosphorus?

A student forgot to add the reaction mixture to the round-bottomed flask at ${27}^{\mathrm{o}} \mathrm{C}$ but instead he/she placed the flask on the flame. After a lapse of time, he realized his mistake, and using a pyrometer he found the temperature of the flask was $477° \mathrm{C}$. What fraction of air would have been expelled out?

Calculate the temperature of $4.0 \mathrm{m}\mathrm{o}\mathrm{l}$ of a gas occupying $5 \mathrm{d}{\mathrm{m}}^3$ at $3.32 \mathrm{bar}$.
$(\mathrm{R}=0.083 \mathrm{b}\mathrm{a}\mathrm{r} \mathrm{d}{\mathrm{m}}^3 {\mathrm{K}}^{-1} \mathrm{mo}{\mathrm{l}}^{-1})$.

Calculate the total pressure in a mixture of $8 \mathrm{g}$ of dioxygen and $4 \mathrm{g}$ of dihydrogen confined in a vessel of $1 \mathrm{d}{\mathrm{m}}^3$ at ${27}^{\mathrm{o}} \mathrm{C}$, $\mathrm{R}=0.083$ $\mathrm{bar} \mathrm{d}{\mathrm{m}}^3 {\mathrm{K}}^{-1} \mathrm{m}\mathrm{o}{\mathrm{l}}^{-1}$.

Payload is defined as the difference between the mass of displaced air and the mass of the balloon. Calculate the payload when a balloon of radius $10 \mathrm{m}$, mass $100 \mathrm{k}\mathrm{g}$ is filled with helium at $1.66$ bar at $27° \mathrm{C}$. (Density of air $=1.2 \mathrm{k}\mathrm{g} {\mathrm{m}}^{-3}$ and $\mathrm{R}=0.083 \mathrm{b}\mathrm{a}\mathrm{r} \mathrm{d}{\mathrm{m}}^3 {\mathrm{K}}^{-1} \mathrm{m}\mathrm{o}{\mathrm{l}}^{-1}$).

Calculate the volume occupied by $8.8 \mathrm{g}$ of $\mathrm{C}{\mathrm{O}}_2$ at ${31.1}^{\mathrm{o}} \mathrm{C}$ and $1$ bar pressure. $\mathrm{R}=0.083$ $\mathrm{bar} \mathrm{L} {\mathrm{K}}^{-1} {\mathrm{mol}}^{-1}$.

$2.9 \mathrm{g}$ of a gas at ${95}^{\mathrm{o}}\mathrm{C}$ occupied the same volume as $0.184 \mathrm{g}$ of dihydrogen at $17\mathrm{}°\mathrm{C},$ at the same pressure. What is the molar mass of the gas?