Question

According to Grahman's law at a given temperature, the ratio of the rates of diffusion $\frac{r_A}{r_B}$of gases A and B is given by
(a)$\left(\frac{P_A}{P_B}\right){\left(\frac{M_A}{M_B}\right)}^{\frac{1}{2}}$
(b)$\left(\frac{M_A}{M_B}\right){\left(\frac{P_A}{P_B}\right)}^{\frac{1}{2}}$
(c)$\left(\frac{P_A}{P_B}\right){\left(\frac{M_B}{M_A}\right)}^{\frac{1}{2}}$
(d)$\left(\frac{M_A}{M_B}\right){\left(\frac{P_B}{P_A}\right)}^{\frac{1}{2}}$
(Where P and M are the pressures and molecular weights of gases A and B respectively)

• A. a
• B. b
• C. c
• D. d

Answer 1

The correct option is C c

r$\propto \frac{P}{\sqrt{M}}$
$\frac{r_A}{r_B}=\left(\frac{P_A}{P_B}\right){\left(\frac{M_B}{M_A}\right)}^{\frac{1}{2}}$