Question

calculate the percentage composition of all the elements present in 34.2 g of sugar

Answer 1

Dear Student,
The chemical name of sugar is sucrose and it has a chemical formula of C₁₂H₂₂O₁₁
Its molar mass is 342 gm
342 gm of sugar contains 144 g of C
34.2 gm will contain $\frac{144}{342}\times 34.2$=14.4 gm
342 gm of sugar contains 22 g H
34.2 gm will contain $\frac{22}{342}\times 34.2$=2.2 g H
342 g sugar contains 176 g O
so 34.2 gm will contain 17.6 g O
% of C = $\frac{14.4}{34.2}\times 100$=42.10%
%H = $\frac{2.2}{34.2}\times 100=6.432\%$
%O= $\frac{17.6}{34.2}\times 100=51.46\%$
Regards!