Molarity, also known as molar concentration, is a measure of the concentration of a chemical species, specifically of a solute in a solution. It is defined as the amount of substance (in moles) of a solute divided by the total volume of the solution (in liters).

The standard unit for molarity is moles per liter (mol/L), often abbreviated as M.

How to Calculate Molarity

The formula for calculating molarity is:

To use this formula, you need to know:

• Moles of Solute (n): This is the amount of dissolved substance. If you have the mass of the solute, you can find the moles using the formula: n = mass / molar mass.
• Volume of Solution (L): This is the total volume of the solution in liters.

Example Calculation

Let's calculate the molarity of a solution prepared by dissolving 58.44 g of sodium chloride (NaCl) in enough water to make 1 liter of solution.

1. Calculate Moles of Solute:
   The molar mass of NaCl is approximately 58.44 g/mol.
   Moles of NaCl = 58.44 g / 58.44 g/mol = 1 mol
2. Apply the Molarity Formula:
   The volume of the solution is 1 L.
   Molarity = 1 mol / 1 L = 1 mol/L (or 1 M)

Therefore, the molarity of the solution is 1 M.