Example Calculation:

Let's say we have a 10% solution of Ammonia (NH₃) with a density of 0.91 g/mL.

Using the formula:

M = (10 × 0.91 × 1000) / (17.03 × 100)

After calculating, the molarity (M) is:

M = 5.34 mol/L

Popular Molar Masses

Molar Masses of Common Substances

Substance	Molar Mass (g/mol)
Ammonia	17.03
Acetic acid	60.05
Ethanol	46.07
Formaldehyde	30.03
Glucose	180.16
Hydrochloric acid	36.46
Hydrogen peroxide	34.01
Nitric acid	63.01<|control704|>
Phosphoric acid	97.99
Potassium hydroxide	56.11
Sodium chloride	58.44
Sodium hydroxide	40.00
Sulfuric acid	98.08

How to Find the Molar Mass of a Substance

The molar mass of a substance is usually equal to its molecular weight. Remember to use the unit g/mol.

How to Calculate the Molecular Weight of Water

To determine the molecular weight of water (H₂O):

1. Look at the periodic table to find the atomic mass of hydrogen (H) and oxygen (O).
2. Hydrogen has an atomic mass of 1 u, and oxygen has an atomic mass of 16 u.
3. Water consists of 2 hydrogen atoms and 1 oxygen atom.
4. Calculate the molecular weight: 2 × 1 u + 1 × 16 u = 18 u.

How to Find Percentage Concentration Given Molarity

If you know the molarity, molar mass, and density of a solution, you can calculate the percentage concentration using the following formula:

The result will be in percent (%).