To 50 g of a 30% solution, 5 g of salt was added. What is the weight fraction of the soluble

To 50 g of a 30% solution, 5 g of salt was added. What is the weight fraction of the soluble substance in the resulting solution?

The mass of salt in the original solution.
m (salt) = W (salt) • m (solution) / 100% = 30% • 50 g / 100% = 15 g.
Total mass of salt.
m (salt) = 15 g + 5 g = 20 g.
The mass of the solution increased after the addition of salt.
m (solution) = 50 g + 5 g = 55 g.
Obtained mass fraction of salt in solution.
W (salt) = m (salt) / m (solution) • 100% = 20 g / 55 g • 100% = 36.4%.