Why is the density of water heavier than the density of alcohol?

Denser, not heavier

Heavier is an inappropriate word. Water is denser than alcohol; it is not heavier. In your question, you should have written greater: Why is the density of water greater than the density of alcohol? Remember, density is defined as mass per unit volume. Examples are pounds per cubic foot (lb/ft³), kiolgrams per cubic meter (kg/m³), and milligrams per milliliter (mg/ml).

You could say that water is heavier per unit volume than alcohol. That is the same as saying water is denser than alcohol.

Think of it another way: Although water is denser than alcohol, a gallon of alcohol is heavier than a teaspoon of water. In other words, to determine which is heavier, you must first know how much you're starting with.

Now, to answer your question!

Water is denser than alcohol because the space between water molecules is less than the space between alcohol molecules. Hence, there is more matter per unit volume of water than per unit volume of alcohol. Since a unit volume of water contains more matter than an identical volume of alcohol, its denisty is greater.

First answer by Schnazola. Last edit by Schnazola. Contributor trust: 1419 [recommend contributor]. Question popularity: 27 [recommend question]