2 mole of `N_(2)O_(4)` (g) is kept in a closed container at 298 K and 1 atmosphere pressure. It is heated to 596 K when 20% by mass of `N_(2)O_(4) (g)` decomposes to `NO_(2)`. The resulting pressure is

Options

A. 2.4 atm
B. 1.2 atm
C. 4.8 atm
D. 2.8 atm

Answer

A

Explanation

Volume of Closed Vessel `(V_(1))=(nRT)/P`
`=(2xx0.0821xx298)/1=48.9 L`
`{:("Initial moles",N_(2)O_(4),hArr,2NO_(2)),("Moles after",2-20/100xx2,,2xx0.4),("dissociation",2-0.4,,0.8" moles"),(,=1.6" mole",,):}`
Total moles present `=1.6+0.8=2.4` moles
`P=(nRT)/n=(2.4xx0.0281xx596)/489=2.4` atm.