A certain public water supply contained 0.10 parts per billion of chloroform CHCl_(3) How many molecules of CHCl_(3)would be contained in a 0.05 ml drop of this water ?

A certain public water supply contained 0.10 parts per billion of chlo

1.	A certain public water supply contained 0.10 parts per billion of chloroform CHCl_(3) How many molecules of CHCl_(3)would be contained in a 0.05 ml drop of this water ?
Answer» Solution :Volume = 0.05 mL Amount of `CHCl_(3)` in th drop `=(0.05 xx 0.1)/10^(5) = 5.0 xx 10^(-12)`g Molecule MASS of `CHCl_(3) = 12+1 + 3 xx 35.5` `=119.5 g mol^(-1)` Moles of `CHCl_(3)` PRESENT `=(5.0 xx 10^(-12))/119.5` MOLECULES of `CHCl_(3)` present in the drop `=(5.0 xx 10^(-12))/119.5 xx 6.022 xx 10^(23) = 2.5 xx 10^(19)`.