Difference Between Hard Water and Heavy Water | Hard Water vs Heavy Water

Key Difference – Hard Water vs Heavy Water

The key difference between hard water and heavy water is their composition as both types, “hard water” and “heavy water” refer to the water with two Hydrogen atoms and one Oxygen atom in the water molecule. When we consider the molecular composition of heavy water, it contains more Deuterium atoms than Hydrogen atoms. The molecular composition of the hard water is same as the normal water, but its mineral composition (Magnesium-Mg and Calcium – Ca) is relatively higher than the soft water.

What is Heavy Water?

A water molecule contains two Hydrogen atoms and an Oxygen atom. Hydrogen has three isotopes; protium (99.98%), deuterium and tritium. Protium has one electron and one neutron. Deuterium has a neutron in the nucleus in addition to the electron and the proton. Deuterium is as twice as heavier than the most abundant Hydrogen atom.

Heavy water contains a large proportion of deuterium atoms than the usual Hydrogen atom. Therefore, its molecular weight and the density is higher than the normal water. It is said that  the density of heavy water is 11 times greater than that of normal water.