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.

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