Question

Calculate the percentage of carbon in ethanedioic acid Crystal

C2H2O4.2H2O.

Answer 1

mm = molar mass
am = atomic mass
%C = (2*am C)*100/mm C2H2O4.2H2O
%H = (6*am H)*100/mm C2H2O4.2H2O
%O = (6*am O)*100/mm C2H2O4.2H2O
Check it to see that the total is 100%.