posted by Charmaine .
An organic pesticide (MW 183.7) is 8.43% Cl. A 0.627-g sample containing the pesticide plus inert material containing no chloride was decomposed with metallic sodium in alcohol. The liberated chloride ion was precipitated as AgCl weighing 0.0831 g. Calculate the percentage of pesticide in the sample.
mass AgCl = 0.0831 g.
moles AgCl = 0.0831/molar mass AgCl = ?
moles AgCl = moles Cl.
?moles Cl x atomic mass Cl = g Cl.
%Cl = (g Cl/g pesticide)*100 = 8.43%
You have %Cl and g Cl, solve for g pesticide, then
%pesticide = (g pesticide/g sample)*100 = ?
Check my work.