what mass of water must be added to 5g of Nacl to make 5% mass by mass percentage of the solution ?????????.............
The mass by mass percentage of a solution is given by the following
mass by mass percentage of solution = (mass of solute / mass of solution) X 100
where mass of the solute = mass of solute + mass of solvent
We are given that the mass of solute is 5g, and the required concentration is 5%. Let the mass of solution be a grams. Hence we will have
5 = (5 / a) X 100
This gives
a = 100g
So, mass of solution = 100g,
and mass of water = (100 - 5) g = 95g
Thus, mass of water to be added is 95 g.