A flask of 1L having `NH_(3)(g)` at 2.0atm and 200K is connected with another flask of vol 800ml having HCl(g) at 8atm & 200K through tube of negligible volume. The two gases reacts to form `NH_(4)Cl(s)` with evolution of 43 KJ/mol heat. If heat capacity of at constant volume is 20J/K/mol and neglecting heat capacity of flask and solid, volume of solid formed and its pressure (R = 0.08).
The final pressure in the flask is

Options

A. 14.39 atm
B. 1.49 atm
C. 16.39 atm
D. 15. 39 atm

Answer

A

Explanation

The heat produced is used to increase the termperature of HCl left in flask since heat capacity of flask and `NH_(4)Cl = 0`
`:. Q = nC_(V) Delta T`
`:. 5.375 xx 10^(3) = 0.275 xx 20 xx Delta T`
`:. Delta T = 977.27 K`
`:.` Final temperature `= 200 + 977.27` = 1177.27K
`rArr` final pressure `= (nRT)/(V)`
`=(0.275 xx 0.08 xx 1127.27)/(1.8) = 14.39` atm