Which of the following property of a small drop of mercury can be used to explain the spherical shape of mercury droplets?

$X \ mL$ of $H_2$ gas effuse through a hole in a container in $5 \ seconds$. The time taken for the effusion of the same volume of the gas specified below under identical conditions is

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 $27^{\circ} C$, a closed vessel contains a mixture of equal weights of helium (mol. wt. = $4$), methane (mol. wt. = $16$) and sulphur dioxide (mol. wt. = $64$). The pressure exerted by the mixture is $210 \ mm$. If the partial pressures of helium, methane and sulphur dioxide are $p_1, p_2$ and $p_3$ respectively, which one of the following is correct?

On what factors does the vapor pressure of a liquid depend?

If $P_1$ is the partial pressure of a gas and $x_1$ is its mole fraction in a mixture,then the correct relation between $P_1$ and $x_1$ is: