Please solve questions 61

Dear Student, rate of effusion is inversely proportional to molar mass. Molar mass of CH4 and SO2 are 16 g/mol and 64 g/mol. Rate of effusion of CH4 to SO2 = √64/16 = 2. It means rate of effusion of CH4 is twice that of SO2. So, double amount of CH4 is effused for that of SO2. Hence, ratio of SO2 to CH4 remaining is 2 : 1. Correct answer is option 2). Regards