What is the $SI$ unit of viscosity?

The ratio of rates of diffusion of oxygen and an unknown gas is $1:4$. The unknown gas is

The total pressure of a mixture of non-reacting gases $X$ $(0.6 \ g)$ and $Y$ $(0.45 \ g)$ in a vessel is $740 \ mm$ of $Hg$. The partial pressure of the gas $X$ is $........ \ mm$ of $Hg$. (Nearest Integer) (Given: molar mass $X = 20 \ g \ mol^{-1}$ and $Y = 45 \ g \ mol^{-1}$)

$A$ gaseous mixture contains equal masses of dihydrogen gas,dioxygen gas and methane gas at a total pressure of $380 \ torr$. The partial pressure of methane gas is ........... $torr$.

At $298 \, K$,equal masses of $SO_2, CH_4$,and $O_2$ are placed in an empty container. The total pressure of the mixture is $2.1 \, atm$. The partial pressure of $CH_4$ in the mixture is ........... $atm$.

When the temperature is raised,the viscosity of a liquid decreases. This is because: