50 mL of gas A effuses through a pin hole in 146 seconds. The same volume of `CO_(2)` under identical condition effuses in 115 seconds. The molar mass of A is

Options

A. 44
B. 35.5
C. 71
D. None of these

Answer

C

Explanation

`("Effusion rate of "CO_(2))/("Effusion rate of "A) = sqrt((M_(A))/(M_(CO_(2))))`
`(50//115)/(50//145) = sqrt((M_(A))/(44))`
`(M_(A))/(44) = (1.27)^(2)`
`:. N_(A) = 71`