Question

Calculate the percentage of carbon, hydrogen and nitrogen in urea. [5]

[ At mass: N= 14, H=1, C= 12 ]​

Answer 1

Explanation:

urea = NH2-CO-NHè

Total Mass =60

Mass of nitrogen =14,2 molecules hence

m=28

N%=mass of nitrogen*100

mass of urea

=28*100

60

N%=46.6%

Answer 2

Explanation:

Formula of urea H2NCONH2

One hydrogen's atomic mass=1

One carbon's atomic mass=12

One Nitrogen's atomic mass=14

One oxygen's atomic mass is =16

Total 4+28+12+16=60

percentage of carbon= 1200/60=20%

percentage of hydrogen=400/60=6.66%

percentage of nitrogen=2800/60=46.6%