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

Total amount of solute present in the mixture is given by,

$300 \times \frac{25}{100} +400\times \frac{40}{100}$

$= 75 + 160$

$= 235 g$
Total amount of solution $= 300 + 400 = 700 g$

Therefore, mass percentage (w/w) of the solute in the resulting solution,$= \frac{235}{700} \times 100\%$

$= 33.57\%$

And, mass percentage (w/w) of the solvent in the resulting solution

$= (100 - 33.57)\%$

$= 66.43\%$