Which statement concerning the vapor pressures of water and methanol (CH₃OH) is true? A) At 25ºC, methanol has a higher vapor pressure than water because methanol has a lower normal boiling point than water. B) At 25ºC, methanol has a higher vapor pressure than water because methanol is a poorer solvent than water. C) At 25ºC, methanol has a higher vapor pressure than water because methanol is a less viscous liquid than water. D) At 25ºC, methanol has a higher vapor pressure than water because the density of methanol is less than the density of water. E) At 25ºC, methanol has a higher vapor pressure than water because methanol has weaker intermolecular forces than water.

Question

Quizplus · Accepted Answer

The vapor pressure of a liquid is inversely proportional to the strength of its intermolecular forces. Methanol has weaker intermolecular forces than water due to the absence of hydrogen bonding, which causes it to have a higher vapor pressure at 25ºC than water.

Which Statement Concerning the Vapor Pressures of Water and Methanol