Question

A sample of drinking water was found to be severely contaminated with chloroform, CHCl3 , supposed to be carcinogen. The level of contamination was 15 ppm (by mass). (i) Express this in per cent by mass. (ii) Determine the molality of chloroform in the water sample. Select the correct answer from above options

Answer 1

Correct Answer - a.15×10-4g,b.1.25×10-25m a. ppm= W2 Weight of solution ×106 15 106 = W2 Weightofsolution % By mass = 15 106 ×100=15×10-4g b. Mw of CHMCl30=119.5g W2=15×10-4g Weight of solution =100g Weight of solvent =W1=(100-15×10-4) =99.998g m= W2×1000 Mw2×W1 = 15×10-4×103 119.5×99.998 =1.25×10-5m