Question

calculate the percentage of nitrogen content by mass in urea, CO(NH2)2.

Answer 1

percentage of nitrogen content by mass in urea is given by =$\dfrac{\ mass\ of \ nitrogen}{molar\ mass \ of\ urea}\times 100$

Molecular formula of urea is given by = $NH_{2}-CO-NH_{2}$

Molar mass of urea = (14+1$\times 2)\times 2 +12 + 16=60 \ g/mol$

Mass of nitrogen in urea =$14\ g/mol \times 2 =28\ g/mol$

% of nitrogen content by mass in urea = $\dfrac{28\ g/mol}{60\ g/mol }\times 100$ =46.6%