Calculate the mass fraction of salt in the solution obtained by adding 50 g of water to 250 g of a 20% potassium chloride solution.

To solve this problem, we use the following calculation methods:
First, we calculate the mass of potassium chloride, for this we multiply the mass by the mass fraction
m (KCl) = 250 g × 0.2 = 50 g
further, knowing the mass of potassium chloride, we find out the mass of water, solve in the following way
m (H2O) = 250 – 50 = 200 g
Next, we calculate the mass fraction of salt in the solution and the result is the following:
W = 50 g salt / (50 g H2O + 50 g salt + 200 g H2O) = 50/300 = 0.167 or 16.7%
The result is the following: the mass fraction of salt is 16.7%.