Answer:
C
Explanation:
There are 3 factors that affect the vapor pressure of a liquid, they are;
surface area
intermolecular forces and
temperature.
If we consider the options, we will notice that NaF is held together by strong ionic bonds in its crystal lattice. Also, CH3CH2OH is held together both by dispersion forces and strong hydrogen bonds.
However, CH3CH2CH2CH3 and CH3CH2CH3 are only held together by weak dispersion forces. Which of them is expected to have the weakest magnitude of intermolecular forces? We must know that larger and heavier molecules exhibit stronger dispersion forces than smaller and lighter ones.
This implies that the magnitude of intermolecular forces in CH3CH2CH2CH3 is much greater than that in CH3CH2CH3. Hence at the same temperature, CH3CH2CH3 has the greatest vapour pressure among the four substances listed in the question.
