Question

How much water should be added to 15 grams of salt to obtain 15 per cent salt solution ?

Answer 1

To make the salt solution of 15% with 15 gm as the mass of the solute, the mass of the solvent must be 85 gm.
$\mathrm{concentration}=\frac{\mathrm{mass}\mathrm{of}\mathrm{solute}}{\mathrm{mass}\mathrm{of}\mathrm{solute}+\mathrm{mass}\mathrm{of}\mathrm{solvent}}\times 100$
Mass of solution = mass of solute + mass of solvent
Mass of the solvent = mass of the solution – mass of solvent
= 100 – 15 = 85 gm
Therefore, 85 gm of water should be added.