Question

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

Answer 1

Step 1: Given data

300 g of 25% solution

400 g of 40% solution

Step 2: Calculating the mass solute

The amount of solute is 300 g of 25% solution is$\frac{25}{100}\times 300=75\mathrm{g}$

The amount of solute is 400 g of 40% solution is$\frac{40}{100}\times 400=160\mathrm{g}$

$\therefore$The total mass of the solute is $75+160=235\mathrm{g}$

Step 3: Calculating the mass percentage

The total mass of the solution is $300+400=700\mathrm{g}$

$\therefore \%$ of solute in the solution is= $\frac{235}{700}\times 100=33.5\%$

$\therefore \%$ of water(solvent) in the solution is= $\left(100-33.5\right)=66.5\%$