What happens when oil is added to water? Why?

When equal volumes of helium and neon at same temperature and pressure are mixed,the ratio $C_p: C_V$ of the mixture equals

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

Which of the following has higher surface tension: pure water or soapy water?

Consider the following statements:
Statement-$I$: If thermal energy is stronger than intermolecular forces,the substance prefers to be in a gaseous state.
Statement-$II$: At constant temperature,the density of an ideal gas is proportional to its pressure.
The correct answer is:

Two gases $X$ (molecular weight $M_{X}$) and $Y$ (molecular weight $M_{Y}$; $M_{Y} > M_{X}$) are at the same temperature $T$ in two different containers. Their root mean square velocities are $C_{X}$ and $C_{Y}$ respectively. If the average kinetic energies per molecule of two gases $X$ and $Y$ are $E_{X}$ and $E_{Y}$ respectively,then which of the following relation$(s)$ is(are) true?