Molar Mass of NaOH

Sodium hydroxide (lye, caustic soda). A strong base made of Na⁺ and OH⁻ ions. It is the classic base in titration problems.

Molar mass of NaOH
39.997 g/mol
1 × 22.99 + 1 × 15.999 + 1 × 1.008 = 39.997

Calculation, element by element

ElementAtomsAtomic mass (g/mol)SubtotalMass %
Sodium (Na)122.9922.99057.48%
Oxygen (O)115.99915.99940.00%
Hydrogen (H)11.0081.0082.52%
Total39.997100%

= 0.25002 mol = 1.5056 × 1023 formula units

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NaOH molar mass FAQ

What is the molar mass of sodium hydroxide (NaOH)?

39.997 g/mol. It is the sum of the atomic masses of every atom in the formula: 1 × 22.99 + 1 × 15.999 + 1 × 1.008 = 39.997 g/mol.

How many grams are in one mole of NaOH?

39.997 g. Molar mass is the mass of one mole (6.022 × 10²³ formula units), so 1 mol of NaOH weighs 39.997 g and 0.5 mol weighs 19.998 g.

How many moles are in 10 g of NaOH?

10 g ÷ 39.997 g/mol = 0.2500 mol.

What is the percent composition of NaOH?

Sodium 57.48%, Oxygen 40.00%, Hydrogen 2.52%.

Is molecular weight the same as molar mass for NaOH?

Numerically yes: the molecular (or formula) weight is 39.997 u per formula unit, and the molar mass is 39.997 g/mol.

Molar masses of other common compounds