How to Calculate Molarity of a Solution?

What is molarity and how do you calculate it?

1. Determine the moles of solute in the solution.

2. Find the volume of the solution in liters.

3. Calculate the molarity by dividing the moles of solute by the volume of the solution.

Molarity Calculation Explained

Molarity is a way to express the concentration of a solution. It is defined as the number of moles of solute dissolved in one liter of solution.

To calculate molarity, you first need to determine the moles of the solute in the solution. This can be done by dividing the mass of the solute by its molar mass.

Next, find the volume of the solution in liters by dividing the given volume in milliliters by 1000.

Finally, calculate the molarity by dividing the moles of solute by the volume of the solution in liters.

Example Calculation:

Suppose you have 15.6 grams of hydroxide (OH-) in a solution with a volume of 105.0 mL. The molar mass of hydroxide is 17.01 g/mol.

1. Calculate the moles of hydroxide:

moles of OH- = 15.6 g / 17.01 g/mol = 0.916 moles

2. Determine the volume of solution in liters:

Volume = 105.0 mL / 1000 = 0.105 L

3. Calculate the molarity of the solution:

Molarity = moles of solute / liters of solution

Molarity = 0.916 moles / 0.105 L = 8.72 M

Therefore, the molarity of the solution is 8.72 M.