Question

Calculate the mass percentage of different constituent elements in urea.

Answer 1

% of element= $\frac{\text{Mass of element}}{\text{Molar mass of element}}\times 100$%

The molar mass of Urea $\left[CO\right(N{H}_2{)}_2]=60.00gmo{l}^{-1}$

$\therefore$ % of nitrogen= $\frac{2\times 14.01}{60.00}\times 100$ %=$46$ %

% of oxygen= $\frac{1\times 16}{60.00}=26.6$ %

% of hydrogen= $\frac{4\times 1}{60.00}=6.7$ %

% of carbon= $\frac{1\times 12}{60.00}=20$ %