How many grams of solute should be added in 100 gm of water to get a solution of density 1.2gm/ ml and strength 5% (w/v)?

Question

Concentration  terms

Answer 1

5% (w/v), by definition, means 5 grams of solute per 100 grams of solution.  Since the density is 1.2 g/ml, you can find the volume of 100 grams of solution.  100 g solution x 1 ml/1.2 g = 83.33 mls.  Hence...

83.33 mls x 5 g/100 mls = 4.17 g solute needed.