Question

A sample of drinking water contains chloroform (chcl3) at a level of 15 ppm (by mass). The percentage by mass of chloroform in the sample is

Answer 1

15 ppm means 15 parts in 1 millions (10^6)

and percentage always for 100


hence 15 ppm = (15/10^6 )*100

= 15*10^-4

= 1.5*10^-3