Question

A solution contains 40 g of common salt in 320 g of water.Calculate the concentration in terms of mass by mass percentage of the solution.

Answer 1

Mass (solute) = 40 gram
Mass (solvent) = 320 gram
Mass (solution) = Mass (solute) + Mass (solvent)
                         = 40 gram + 320 gram
                         = 360 gram
∴ Mass % (solution) = [ Mass (solute)/Mass (solvent)] × 100
                                 = [40/360] × 100
                                 = 11.1 %

Answer 2

Mass of solute - NaCl =40gm

Mass of solvent - water =320gm

Mass of solution =(40+320) gm

=360gm

Concentration in terms of Mass by mass percentage =mass of solute /mass of solution *100

=40/360*100%=11.11%