19. Calculate number of atoms of hydrogen present in 5.6 g of urea (mo

1.	19. Calculate number of atoms of hydrogen present in 5.6 g of urea (molar mass of urea= 60g mol-1). Also calculate number of atoms of N, C and O.
Answer» Urea = NH2CONH2 M.wt = 60 5.6 g urea = 5.6/60 = 0.093 moles 1 mole of urea contains 4N atoms of H 0.093 moles contains 0.093 x 4N atoms of H = 2.24 x 10^23 atoms of H No of atoms of Nitrogen = half of the number of atoms of H = 1.12 x 10^23 atoms of N No of atoms of C or O = half of the number of atoms of N = 0.56 x 10^23 atoms of C or O = 5.6 x 10^22 atoms of C or O

19. Calculate number of atoms of hydrogen present in 5.6 g of urea (molar mass of urea= 60g mol-1). Also calculate number of atoms of N, C and O.

Answer»

Urea = NH2CONH2

M.wt = 60

5.6 g urea = 5.6/60 = 0.093 moles

1 mole of urea contains 4N atoms of H

0.093 moles contains 0.093 x 4N atoms of H

= 2.24 x 10^23 atoms of H

No of atoms of Nitrogen = half of the number of atoms of H

= 1.12 x 10^23 atoms of N

No of atoms of C or O = half of the number of atoms of N

= 0.56 x 10^23 atoms of C or O

= 5.6 x 10^22 atoms of C or O