The rate of diffusion of \[SO_{2},CO_{2},PCI_{3} and SO_{3}\]     are in the following order
a) \[PCI_{3}> SO_{3}>SO_{2}>CO_{2}\]
b) \[CO_{2}>SO_{2}>PCI_{3}> SO_{3}\]
c) \[SO_{2}> SO_{3}>PCI_{3}>CO_{2}\]
d) \[CO_{2}>SO_{2}> SO_{3}>PCI_{3}\]

Answer: d
Explanation: \[Rate \propto \sqrt{\frac{1}{M}} \]    The smaller the value of M the more is the rate of diffusion