How much water should be added to 15 grams of salt to obtain 15 per cent salt solution ?
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.
`"concentration" = "mass of solute"/"mass of solute + mass of solvent"xx 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.