Question

The mass percentage of nitrogen in urea (

${NH}_2{CONH}_2$

) is .

• A. 85.92
• B. 46.67
• C. 18.23
• D. 28.58

Answer 1

The correct option is B 46.67

Molecular mass of urea ($N{H}_{2}CON{H}_2$) is
= 2$\times$ (Atomic mass of N ) + 4 $\times$ (Atomic mass of H) + (Atomic mass of C) + (Atomic mass of O) = 60

Mass percentage of N = $\frac{\text{Total mass of N atoms in the compound}}{\text{Mass of compound}}\times 100=\frac{28}{60}\times 100=46.67\%$