To 300 g of a solution of barium chloride, a mass fraction of 20%, 200 ml

To 300 g of a solution of barium chloride, a mass fraction of 20%, 200 ml of water was added. Determine the mass fraction in the resulting solution.

Given:

m (BaCl2 solution) = 300 g;

w% (BaCl2) = 20%;

V (H2O) = 200 ml;

Find:

% (BaCl2 in the final solution) -?

Solution:

1) Find the mass of salt in the solution:

m (BaCl2) = 300 g * 0.2 = 60 g;

2) Find the mass of added water:

m (H2O) = p * V = 1 g / ml * 200 ml = 200 g;

3) Find the mass of the solution after adding water:

m (solution) = 300 g + 200 g = 500 g;

4) Find the mass fraction of salt in the solution:

w% (BaCl2) = m (BaCl2): m (solution) * 100% = 60 g: 500 g * 100% = 12%.

Answer: w% (BaCl2) = 12%.