Question

4. The solution of sodium chloride in water is 25% w/v. The density of the solution is 1.15 g/ml.Express the concentration of the solution w/w.​

Answer 1

25g of NaCl in 100ml solution

density of solution = 1.15g/ml

Mass of solution = Volume x Density = 100 x 1.15 = 115g

Therefore, concentration in w/w = (Mass of solute/ Mass of solution) x 100 = (25/115) x 100 = 21.7%