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 the closed vessel (V)`=(nRT)/(P)`
`=(2xx0.0821xx298)/(1)=48.9" L"`
`N_(2)O_(4) hArr 2NO_(2)`
`{:("Initial moles",2,0),("Moles after",2-(20)/(100)xx2,2xx0.4),("dissociation",=2-0.4,=0.8" mole"),(,=1.6"mole",):}`
Tota moles present after heating`=1.6+0.8`
`=2.4" moles"`
`P=(nRT)/(V)=(2.4xx0.0821xx596)/(48.9)=2.4" atm"`