Q. A gas is found to have formula$\lbrack CO\rbrack_{x}$. Its vapour density is 70, the $x$ is
A) 3.0
B) 3.5
C) 5.0
D) 6.5
Explanation
(c)
Given, vapour density=70
$\therefore$ Molecular weight=$2 \times$ vapour density
$= 2 \times 70 = 140$
$\lbrack CO\rbrack_{x} = (12 + 16)_{x} = (28)_{x}$
$\because$ $(28)_{x} = 140$
$x = \frac{140}{28} = 5$
$\therefore$ Formula is $(CO)_{5}$.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.