At which of the following conditions is the density of a gas maximum?

What is meant by payload?

Sulphur dioxide $(SO_2)$ and oxygen $(O_2)$ were allowed to diffuse through a porous partition. $20 \ dm^3$ of $SO_2$ diffuses through the porous partition in $60 \ seconds$. The volume of $O_2$ in $dm^3$ which diffuses under the similar conditions in $30 \ seconds$ will be (atomic mass of sulphur $= 32 \ u$)

$A$ container consists of a mixture of four gases: $5 \text{ g } H_2$,$8 \text{ g } He$,$50 \text{ g } CO_2$,and $20 \text{ g } Ne$ at a certain temperature. Which of the following gases exerts the minimum partial pressure?

Normal boiling point of water is $373 \ K$ (at $760 \ mm$). Vapour pressure of water at $298 \ K$ is $23 \ mm$. If the enthalpy of evaporation is $40.656 \ kJ/mole$,the boiling point of water at $23 \ mm$ pressure will be ............. $K$.

Which physical property decreases with an increase in intermolecular forces?