Question

Why does acetone evaporate faster than hexane?

a. Acetone has a lower boiling point.
b. Acetone has stronger intermolecular forces.
c. Hexane has a lower vapor pressure.
d. Hexane has higher viscosity.

Answer 1

Hexane has a lower vapor pressure, resulting in slower evaporation compared to acetone.

Step-by-step explanation:

The correct answer is c. Hexane has a lower vapor pressure.

Acetone evaporates faster than hexane because it has a lower vapor pressure. Vapor pressure is the pressure exerted by the vapor of a substance in equilibrium with its liquid phase at a given temperature. A higher vapor pressure means that more molecules of the substance are able to escape from the liquid and enter the gas phase.

Hexane, on the other hand, has a lower vapor pressure, which means that fewer molecules are able to escape from the liquid and enter the gas phase. This is because hexane has weaker intermolecular forces compared to acetone, resulting in fewer molecules having the necessary kinetic energy to overcome the attractive forces and evaporate.