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.

Let the first solution be solution A and second solution be solution B.

Given:

⇒ Mass of Solute in solution A, M_a = [25 × 300]/100

= 75g

⇒ Mass of Solute in solution B, M_b = [40 × 400]/100

= 160g

To find: Mass Percentage of Solute

Formula:

Mass Percentage of Solute

Solution:

⇒ Total mass of Solute in mixture, M = M_a + M_b

= [75 + 160]

= 235g

⇒ Total mass of solution = 300 + 400

= 700g

⇒ Mass Percentage of Solute

= 33.5%

⇒ Percentage of Water in final solution = 100-33.5

= 66.5%

Therefore mass percentage of solute is 33.5% and that of water is 66.5%.