Amixture of two gases was allowed to effuse from a container. one of the gases escaped from the container 1.43 times as fast as the other one. the two gases could have been: a) co and sf6
b) o2 and cl2
c) co and co2 d) cl2 and sf6
e) o2 and sf6

The two gases are and  

Explanation:

According to Graham law of effusion for a binary mixture of gases-

Where and are rate of effusion of gas-1 and gas-2 respectively. and are molar mass of gas-1 and gas-2 respectively.

                             Gas                               Molar mass (g/mol)

                                                                 32

                                                                 71

                                   CO                                         28

                                                                44

                                                                 146

So, clearly molar mass of is greater than molar mass of . Hence will effuse faster.

Also,

Hence, option (d) is correct.