Question

5. An organic compound containing
oxygen, carbon, hydrogen and nitrogen
contains 20 % carbon, 6.7 % hydrogen
and 46.67 % nitrogen. Its molecular
mass was found to be 60. Find the
molecular formula of the compound.
(Ans.:CH4N2O​

Answer 1

Answer:

Consider given percentages of elements as their mass..

C= 20 g

H=6.7 g

N=46.67 g

then convert these masses into moles.

C=20/12 = 1.66

H=6.7/1= 6.7

N=46.67/14= 3.33

THEN find simple mole ration by diving all these three value by the smaller one.

C= 1.66÷1.66= 1

H= 6.7÷1.66= 4

N= 3.33÷1.66= 2

CH4N2O

Hope it helps u

Answer 2

★Relative no of atoms

• Simply divide the % quantity of the elements with thier atomic masses

→ C = 20 / 12 = 1.66

→ H = 6.7 / 1 = 6.7

→ N = 46.67 / 14 = 3.33

→ O = 26.63 /16 = 1.66

★ Simple ratio :-

• Divide all the values obtained above with the least value

→ C = 1.66 / 1.66 = 1

→ H = 6.7 / 1.66 = 4

→ N = 3.33 / 1.66 = 2

→ O = 1.66 / 1.66 = 1

♣ Empirical formula = C H 4 N 2 O

♣Empirical mass = 12 + 4 + 24 + 16 = 60 g

→ Molecular mass = 60 g (given)

we know that ,

→ Molecular mass = n ( Empirical mass )

→ n = Molecular mass / Empirical mass

→ n = 60 / 60

→ n = 1

Hence from this we can conclude that ,

→ Empirical formula = molecular formula

Molecular formula = C H 4 N 2 O