A definite amount of solid `NH_(4)HS` is placed in a flask aleady containing ammoina gas at a certain temperature and `0.50` atm pressure. `NH_(4)HS` decomposes to give `NH_(3)` and `H_(2)S` and at equilibrium total pressure in flask is `0.84` atm. The equilibrium constant for the reaction is:

Options

A. `0.30`
B. `0.18`
C. `0.17`
D. `0.11`

Answer

D

Explanation

`{:(NH_(4)HS_((s)),hArr,NH_(3(g)),+,H_(2)S_((g))),("Before eq".,,0.5,,0),("After eq".,,0.5+P,,p):}`
`P_(T) = 0.84 = 0.5 + P + P`
`:. P = 0.17` atm
`K_(p) = P'_(NH_(3)) xx P'_(H_(2)S)`
`=(0.5+0.17)xx0.17 = 0.11 atm^(2)`