To 600 g of a 5% potassium sulfate solution was added 20 g of this salt.

To 600 g of a 5% potassium sulfate solution was added 20 g of this salt. Find the mass fraction of potassium sulfate in the resulting solution.

Given: m1 (solution) = 600 g; W1 (K2SO4) = 5%; m2 (K2SO4) = 20 g. Find W2 (K2SO4) =?
We calculate the mass of potassium sulfate in the original solution:
m1 (K2SO4) = 600 * 5/100 = 30 g.
After adding, the mass of the solution became:
m2 (solution) = 600 + 20 = 620 g.
Salt mass:
m3 (K2SO4) = 30 + 20 = 50 g.
We consider the mass fraction:
W2 (K2SO4) = (50/620) * 100 = 8.06%