Question

A solution is obtained by mixing 300 g of 25% solution and 400 g of 40% solution by mass. Calculate the mass percentage of the resulting solution.

Answer 1

300 g of 25% solutions contains solute = 75 g 

400 g of 40% solution contains solute = 160 g. 

Total solute = 160 + 75 = 235 g 

Total solution=300 + 400 = 700 g 

% of solute in final solution = \(\frac{235}{700}\) × 100 = 33.5% 

% of water in the final solution = 100 - 33.5 = 66.5%