How do I calculate concentration from density?

The first step is to divide the solute’s mass by its molar mass. For example, if the solution has 20 grams of sodium chloride, (which has a molar mass of 58.44 mg/mol), 20 / 58.44 = 0.342 moles. 

Then, the mass of the solute must be added to the mass of the solute. If the sodium chloride is dissolved in 50 grams of water, 20 + 50 = 80. 

Next, this sum should be divided by the solution’s density. If the density is 1.53 grams per cubic cm: 80 / 1.53 = 52.29 cm^3. This answer is the solution’s volume. 

Next, in order to convert to liters, the volume must be divided by 1,000.

52.29 / 1000 = 0.052. 

The last step is to divide the answer from step 1 (0.342) by the answer to step 4 (0.052).

0.342 / 0.052 = 6.58 moles per liter.