QJEEM02Ch8116: JEE Main 2002 Chemistry - Class 11 JEEM02Ch8116 Solution: In a compound C, H and N atoms are present in 9 : 1 : 3.5 by…

Element	Weight ratio	No of atoms of element	Simplest Ratio
C	9	9/12 = 3/4	3
H	1	1/1 = 1	4
N	3.5	3.5/14 = 1/4	1

Empherical Formula of the compound (EF) will be C₃H₄N

Now to find molecular formula at first find number of moles of given mass

No. of moles (n) =

Given mass

Molar mass

$$\Rightarrow$$ $$\frac{108}{54}$$

$$\Rightarrow$$ 2

$$\therefore$$ No. of Moles is 2

Molecular formula (MF) = n (no. of moles) $$\times$$ Empherical Formula (EF)

$$\Rightarrow$$ 2 $$\times$$ C₃H₄N

$$\Rightarrow$$ C₆H₈N₂

$$\therefore$$ Option (C) is correct