How to prepare 80 grams of 5% sodium chloride solution?

The mass of the solution is 80 grams;

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

m salt = 80 x 0.05 = 4 grams;

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

m of water = 80 – 4 = 76 grams;

The density of water is 1 gram / cm3. To prepare this solution, it is necessary to measure 76 milliliters of water, and then dissolve a weighed portion of salt in it.

Check: 76 + 4 = 80;