Question

The time taken for a certain volume of a gas ‘X’ to diffuse through a small hole is 2 minutes. It takes 5.65 minutes for oxygen to diffuse under the similar conditions. The molecular weight of ‘X’ is

• A. 8
• B. 4
• C. 16
• D. 32

Answer 1

Answer: (B)

4

Answer 2

$\frac { r _ { X } } { r _ { O _ { 2 } } } = \sqrt { \frac { M _ { O _ { 2 } } } { M _ { X } } }$

$\frac { v / 2 } { v / 5.65 } = \sqrt { \frac { 32 } { M _ { X } } } , \frac { 5.65 } { 2 } = \sqrt { \frac { 32 } { M _ { X } } } , M _ { X } = 4$