Question

A gas is found to have a formula (CO)x . If its vapour density is 70,Then value of x is (1) 2 (2) 3 (3) 5 (4) 6

Answer 1

"Mol. Wt. =2*vapour density

hence, Mol Wt. Of carbon =12u

Mol Wt. Of O=16u

Mol Wt. Of (CO) x =(12+16)x =28x

Now, According to Formula

28x =2*70

28x =140

x=5 is possible value

Molecular mass is equal to 2 X vapour density 2 X 70 is equal to x times atomic mass of carbon + atomic mass of oxygen

(12 + 16 )x = 28 x show 28 x = 140 and x = 5

"

Answer 2

According to the Question

Vapour density = 70

Molecular Mass = 2 × 70

= 140

Formula of COx :-

Molecular Mass ⇒ (12 + 16)x = 140

⇒ x × 28 = 140

${\implies x = \dfrac{140}{28}}$

x = 5