Determine the mass of salt and water that will be required to prepare 120g of a 2% solution.

The mass of the solution is 120 grams;

To find the mass of salt, it is necessary to multiply its mass fraction by the mass of the solution.

m salt = 120 x 0.02 = 2.4 grams;

To find the mass of water, subtract the mass of salt from the mass of the solution:

m of water = 120 – 2.4 = 117.6 grams;

The density of water is 1 gram / cm3. To prepare this solution, measure 117.6 milliliters of water.

Check: 117.6 + 2.4 = 120;