# Molar Mass of NaOH

This write-up computes the molar mass of sodium hydroxide for you, besides explaining all the basic analytical chemistry concepts involved.

Omkar Phatak

Last Updated: Sep 22, 2018

Definition

Molar mass or gram mole of any compound is its exact molecular weight (computed from summing up of atomic weights together) expressed in grams. It is generally expressed in grams or gram/mol. One mole is unit molar mass of that substance, expressed in grams. For example, one gram mole of water is 18 gm or 18 gm/mol.

Calculation Technique

You may know sodium hydroxide (NaOH) as 'caustic soda' or 'lye', as it finds many applications in the manufacturing of soaps, detergents, and even textiles. Its wide applicability is owed to it being a strong base.

Calculation

Firstly, we need to know the atomic weights of hydrogen and oxygen. While sodium's standard atomic weight is 22.98976928, hydrogen's standard atomic weight is 1, and oxygen has a standard atomic weight of 15.9994.

**39.9892 gm/mol**. The value has been rounded up only after the fourth decimal, as measurements in chemistry need to be as accurate as possible.