Question

According to Graham’s law, the rate of diffusion of $CO, O_{2,} N_{2}$ and $CO_{2}$ follows the order

• A. $CO = N_2 > O_{2} > CO_{2}$
• B. $CO = N_{2} > CO_{2} > O_{2}$
• C. $O_{2} > CO = N_{2} > CO_{2}$
• D. $CO_{2} > O_{2} > CO = N_{2}$

Answer 1

Answer: (A)

According to Graham’s law, rate of diffusion is inversely proportional to the square root of molar mass, i.e.
$r\propto\frac{1}{\sqrt{M}}$
Thus, rate of diffusion decrease with increase in molecular weight. Therefore, the order of rate of diffusion will be
$CO = N2 > O_{2} > CO_{2}$
$(28\, g) (28\, g) (32\, g) (44\, g)$