Question

Ratio of molecular weights of $A$ and $B$ is $\frac{4}{25}$ then ratio of rates of diffusion will be:

• A. 5:01
• B. 5:02
• C. 25:03:00
• D. 25:04:00

Answer 1

Answer: (B)

5:02

Answer 2

The problem can be solved with the help of Graham's rule. The formula to be used is as follows: $\frac{r_{1}}{r_{2}}=\sqrt{\frac{M_{2}}{M_{1}}}$ Given, $M_{1}=4,$ $M_{2}=25$ Substituting values, $\frac{r_{1}}{r_{2}}=\sqrt{\frac{25}{4}}=\frac{5}{2}$ $\therefore$ Ratio of rate of diffusion $=5: 2$