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

Mass of solute in 300 g of 25% solution

\(\frac{300\times25}{100}\) = 75g

Mass of solute in 400 g of 40% solution

\(\frac{400\times40}{100}\) = 160g

Total mass of solute = (75 + 160) g = 235 g

Total mass of solution = (300 + 400) g = 700 g

Mass % of solute in resulting solution = \(\frac{235\times100}{700}\)

= 33.57%

Mass % of solvent (water) in resulting solution

= 100 – 33.57 = 66.43%