At a constant temperature and pressure,the ratio of the densities of two gases is $1 : 16$. The ratio of their rates of diffusion will be ........

Fill in the blanks:
$(1)$ The properties of gases were first measured by ......... .
$(2)$ The dipole-dipole interaction energy between stationary polar molecules is proportional to .......... .
$(3)$ The interaction energy between rotating polar molecules is proportional to .......... .
$(4)$ The bond energy of a hydrogen bond is about ......... $kJ \ mol^{-1}$.

Who among the following scientists has not done any important work on gases?

It is recommended that a liquid ammonia bottle should be opened after cooling it in ice for some time. This is because liquid ammonia:

At $T \ K$,a gaseous mixture of $H_2$ and $O_2$ containing $20 \%$ (weight/weight) of $H_2$ exerts a total pressure of $2 \ bar$. What is the partial pressure of $O_2$ (in bar)?

Which physical property decreases with an increase in intermolecular forces?