mC = 3.96x12/44 = 1.08 (g)
mH = 0.72x2/18 = 0.08 (g)
mO = 1.32 - (1.08 + 0.08) = 0.16 (g)
%C = 1.08x100/1.32
%H = 0.08x100/1.32
%O = 0.16x100/1.32
CT: CxHyOz
Theo đề bài ta có: x : y : z = 1.08/12:0.08/2:0.16/16
=> x:y:z = 0.09 : 0.04 : 0.01 = 9:4:1