How does molecular weight affect vapor pressure? Chemistry Matter Atomic Mass 1 Answer anor277 Jun 27, 2016 The vapour pressure of a solution is always lower than that of the pure solvent. Explanation: See this site. Given that vapor depression is a colligative property, dependent on the number of moles of solute in solution, solutes with lower molecular mass should cause less vapor pressure depression. Answer link Related questions How do you calculate the atomic mass of carbon? How are atomic mass and mass number different? How do you calculate atomic mass from isotopic composition ? How do atomic mass and atomic weight differ? How do atomic masses reflect isotope abundances? How do atomic masses vary throughout the periodic table? How much atomic mass is in hydrogen? What atomic mass does ekasilicon have? Why are atomic masses of most of the elements fractional? What is atomic mass? See all questions in Atomic Mass Impact of this question 9400 views around the world You can reuse this answer Creative Commons License