Consider a gas at temperature T occupying a volume V consisting of a mixture of two gases having `N_(a) & N_(b)` atoms of masses `m_(a) & m_(b)` respectively.
Suppose that `N_(a)=N_(b)` the different atoms combine at constant volume to form molecules of mass `m_(a)+m_(b)`. Once the temperature returns to its original value, what would be the ratio of the pressure after combination to the pressure before?

Options

A. 1
B. `1//3`
C. `1//2`
D. none

Answer

C

Explanation

After getting combined the no. of moles becomes half in this case :. At const. V and T
`P propto n`
:. P becomes half