Embibe Experts Solutions for Chapter: States of Matter, Exercise 1: BITSAT 2017

The density of a certain gas at ${30}^0\mathrm{C}$ and $768$ torr is $1.35 \mathrm{kg}/{\mathrm{m}}^3$, then density of the gas at $\mathrm{STP}$ is

Four gases $\mathrm{P}, \mathrm{Q}, \mathrm{R}$ and $\mathrm{S}$ have almost same values of $\mathrm{b}$ but their $\mathrm{a}$ values $(\mathrm{a} \& \mathrm{b}$ are van der Waal s' constant) are in the order $\mathrm{Q}<\mathrm{R}<\mathrm{S}<\mathrm{P}$. At a particular temperature, among the four gases, the most easily liquifiable one is

One moles each of four ideal gases are kept as follows. 

I. $5 \mathrm{L}$ of gas $\left(\mathrm{A}\right)$ at $2 \mathrm{atm}$ pressure

II. $2.5 \mathrm{L}$ of gas $\left(\mathrm{B}\right)$ at $2 \mathrm{atm}$ pressure

III. $1.25 \mathrm{L}$ of gas $\left(\mathrm{C}\right)$ at $2 \mathrm{atm}$ pressure

IV. $2.5 \mathrm{L}$ of gas $\left(\mathrm{D}\right)$ at $2.5 \mathrm{atm}$ pressure

Which of the above gases is kept at highest temperature.