Question

Q.5 A compound having the molecular formula C, H,, gave the following PMR data.
() Singlet t 9.12 (8 0.88) 9H (ii) Singlet t 2.72 (87.28) 5H
Assign the structure on the basis of above data.​

Answer 1

Answer:

Explanation:

Find ratio of atoms, empirical formula, n and molecular formula.

Given, C:H:N=9:1:3.5 (ratio of weights)

Mol.wt.=108

Element Ratio of wt. Ratio of atoms Simplest ratio

C 9 9/12=0.75 0.75/0.25=3

H 1 1/1=1 1/0.25=4

N 3.5 3.5/14=0.25 0.25/0.25=1

∴ Empirical formula =C  

3

​  

H  

4

​  

N

Empirical formula wt.

=12×3+1×4+14=54

n=  

empirical formula wt.

mol.wt.

​  

=  

54

108

​  

=2

Molecular formula = empirical formula ×n

=2(C  

3

​  

H  

4

​  

N)

=C  

6

​  

H  

8

​  

N  

2

​