Which gas volume is measured in a sample by using a solution of $CuCl$ in $NH_4OH$ through the measurement of volume change?

Write the formula to calculate the pressure of a dry gas collected over water.

Two gases $A$ and $B$ having the same volume,effuse through an orifice in $30$ and $10$ minutes respectively. The molar mass of $A$ is $162$. The molar mass of $B$ will be

Where will the boiling point be lower: at the seashore or on a mountain? Why?

The normal boiling point of water at $760 \, mm$ is $373 \, K$. The vapor pressure of water at $298 \, K$ is $23 \, mm$. If the enthalpy of vaporization is $40.656 \, kJ/mol$,then its boiling point at $23 \, mm$ pressure will be ........... $K$.

At a certain temperature and pressure,helium diffuses $n$ times faster than methane. Find the value of $n$.