How many grams of a substance is required to prepare 150 grams of a 5% sodium chloride solution?

The mass of the solution is 150 grams;

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

m salt = 150 x 0.05 = 7.5 grams;

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

m of water = 150 – 7.5 = 142.5 grams;

The density of water is 1 gram / cm3. To prepare this solution, you need to measure out 142.5 milliliters of water.

Check: 142.5 + 7.5 = 150;