Why is ethanol less dense than water?

The density is defined as mass per unit volume.Ethanol has a less density relative to water.The boiling point of ethanol is lower than that of water due to its tendency of strong Hydrogen bonding. If a molecule has a large size a large space will be occupied by the single molecule. read more

Water is a little bit denser than alcohol. This fact can be validated by putting equal volume of water and alcohol (ethanol in this case) on a balance, the water will be heavier than the ethanol. read more

The reason why the volume decreased because the ethanol molecules are smaller than the water molecules. So, the ethanol molecules get crammed in between the water molecules. That’s why there was a decrease in volume. read more