The reaction of dimerisation of `NO_(2)` in `N_(2)O_(4)` is `2NO_(2)hArrN_(2)O_(4)`. The reaction is carried out by taking `1` mole each of `NO_(2)` and `N_(2)O_(4)` in a closed vessel of `1` litre at `400 K`. The equilibrium pressure was found to be `77 atm`.
After attaining the equilibrium, `1` mole of `N_(2)O_(4)` is added in the quilibrium mixture.The total pressure at equilibrium would be:

Options

A. `65.2 atm`
B. `121.5 atm`
C. `140.0 atm`
D. `128.2 atm`

Explanation

`{:(N_(2)O_(4),hArr,2NO_(2)),(2,,1),((2-x),,(1+2x)):}`
`K_(c)=((1+2x)^(2))/((2-x))=4.44`
`:. X=0.7`
Total mole `=3+x=3+0.7=3.7`
`=121.50 atm`