Consider 55 mL of water (H2O) in a beaker and 55 mL of acetone [(CH3)2CO] in an identical beaker under identical conditions. Complete the sentences to explain the relationship between the vapor pressure of water and acetone.

More slowly than

Larger than

Weaker

Explanation:

The vapor pressure of a solution describes how quickly a solution will turn into vapour. If we say that a solution has a high vapour pressure, we are actually saying that the solution turns into vapour more quickly.

Acetone has a higher vapour pressure than water so acetone turns to vapour quicker than water.

Vapour pressure has a lot to do with the magnitude of intermolecular forces in solution. The stronger the magnitude of intermolecular forces, the lower the vapor pressure and the more slowly the solution evapourates.

So, the hydrogen bonds in water provides stronger intermolecular forces than dispersion and dipole interaction in acetone. Hence, water vaporizes more slowly than acetone.