Question

on evaporation of 2.72 g of saturated solution of a substance, we obtained 0.72 g of precipitate.the solubility of substance would be

Answer 1

According to given condition;

Mass of Solute(precipitate) = 0.72 gm 

Mass of Solvent  = Mass of Solution - Mass of Solute
                               = 2.72gm - 0.72gm
                               = 2 gm

Using the Formula , 
Solubility of Substance = {Mass of Solute/Mass of Solvent }x 100%
                                      = {0.72/2 } x 100%
                                      = 36%
 
Thus the solubility of Substance is 36% .

hope it will help!