Question

Calculate the number of hydrogen atoms present in the in 40g of urea

Answer 1

Molecular formula of urea CON

2

H

2

Molar mass of urea = 60gmol

−1

Number of moles of urea = n=

M

W

=

60

5.6

=0.09333mol

Now,

∴ 1 mol urea contains 4 gram atoms of hydrogen(H)

∴ 0.09333mol urea contains==4×0.09333=0.3733 gram atom of H.

Now,

1gm atom of H contains =6.022×10

23

atoms of H.

0.3733gram atom of hydrogen contains = 6.022×10

23

×0.3733=2.248×10

23

Conclusion: Number of H atoms = 2.248×10

23