One mole of an ideal gas at $300 \ K$ is expanded isothermally from $1 \ L$ to $10 \ L$ volume. $\Delta U$ for this process is $....... \ J$ (Use $R = 8.314 \ J \ K^{-1} \ mol^{-1}$)

If a gas occupies $1 \, L$ volume at atmospheric pressure,what will be the volume of the same amount of gas at $750 \, mm \, Hg$ pressure at the same temperature?

The correct value of the gas constant $R$ is close to

Calculate the number of moles of the gas having volume $2.5 \ L$ at $300 \ K$ and $4.5 \ atm$? $(R=0.0821 \ atm \ dm^3 \ K^{-1} \ mol^{-1})$

Geraniol,a volatile organic compound,is a component of rose oil. The density of the vapour is $0.46 \, g \, L^{-1}$ at $257^{\circ} C$ and $100 \, mm \, Hg$. The molar mass of geraniol is $....$ (Nearest Integer) [Given $R = 0.082 \, L \, atm \, K^{-1} \, mol^{-1}$]

$A$ student forgot to add the reaction mixture to the round bottomed flask at $27^{\circ} C$ 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 $477^{\circ} C$. What fraction of air would have been expelled out?