An amount of solid `NH_4HS` is placed in a flask already containing ammonia gas at a certain temperature and 0.50 atm pressure.Ammonium hydrogen sulphide decomposes to yield `NH_3` and `H_2S` gases in the flask.When the decomposition reaction reaches equilibrium, the total pressure in the flask rises to 0.84 atm ? The equilibrium constant for `NH_4HS` decomposition at this temperature is :

Options

A. 0.11
B. 0.17
C. 0.18
D. 0.3

Answer

A

Explanation

`NH_(4) HS_((s)) Leftrightarrow NH_(3)(g)+H_(2)S(g)`
`{:(,"Initial pressure",0,0,5,0),(,"At equilibrium",0,0.5+x,x):}`
total pressure =0.5+2x=0.84 x=0.17 atm
`K_(p)=P_(NH_(3)) xx P_(H_(2)S)=0.11 atm^(2)`