Question

.1) An organic substance containing carbon, hydrogen and oxygen gave the following percentage composition. C = 40.687%, H=5.085% and O=54.228%. The molecular weight of an organic compound is 118. Determine the:-
a) Empirical formula
b) Molecular formula

Answer 1

Answer:

Correct option is B)

Consider →100 g of compound

Masses Molar mass Moles Ratios Ratio

C 40.3687 12 3.3916 3.4/3.4=1 2

H 5.085 1 5.085 5.1/3.4=1.5 3

O 54.228 16 3.392 3.4/3.4=1 2

Emperical formula =C

2

H

2

O

2

Emperical mass =2×12+3×1+2×16

=24+3+32

=59

Molecular mass =2×vapor density =2×59=118

n=

E.M

M.M

=

59

118

=2

Molecular formula =n×E.F=2×C

2

H

3

O

2

=C

4

H

6

O

4

hope this helps you ❤