Does Rubbing Alcohol Evaporate Faster Than Water?


4 Answers

Mark Henderson Profile
Mark Henderson answered
Yes rubbing alcohol does indeed evaporate faster than water, even though it has a higher molecular weight than water does.

Water is one of the slowest evaporating liquids for it's mass, and that is because of the complexity of the bonds between its molecules.

  • Rubbing alcohol (also known as ethanol) evaporates much quicker than water does.
  • Water is one of the slowest evaporating liquids relative to its mass.
  • Ethanol has a higher molecular weight but still evaporates faster.
  • The molar mass of water is 18g/mol whilst rubbing alcohol is 60g/mol.

Why does rubbing alcohol evaporate faster than water?

The reason why rubbing alcohol evaporates faster than water is purely down to the molecular bonds in both substances.

  • The hydrogen bonding in water means that the oxygen and hydrogen form bonds with other water molecules, which makes water a substance which is almost "weaved" together.
  • In contrast, alcohol can also form some hydrogen bonds like water, but because the carbon in rubbing alcohol cannot hydrogen bond as well, the molecules are less "attached" to one another. Therefore they evaporate faster. 
Anonymous Profile
Anonymous answered
Yes, rubbing alcohol molecules have less hydrogen bonding than water, so, even though the molecular weight of the alcohol is much higher than water, it evaporates easier.
Anonymous Profile
Anonymous answered

 I think yes cause rubbing alcohol has more bonding molecules than water and water evaporates slower - it's the slowest evaporating liquid. I think that rubbing alcohol is the fastest evaporating liquid.

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