A small amount of NH_(4)HS is placed in a flask already containing ammonia gas at a certain temperature and 0*50 atm pressure. Ammonium hydrogensulphide decomposes to yield NH_(3) andH_(2)S gass 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_(4)HS decomposition at this temperature is

A small amount of NH_(4)HS is placed in a flask already containing amm

1.	A small amount of NH_(4)HS is placed in a flask already containing ammonia gas at a certain temperature and 0*50 atm pressure. Ammonium hydrogensulphide decomposes to yield NH_(3) andH_(2)S gass 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_(4)HS decomposition at this temperature is
Answer» `0.30` `018` `017` `0*11` Solution :`{:(,NH_(4)HS (s),HARR,NH_(3) (g),+,H_(2)S (g)), ("Intial",a " moles",,0.5" atm",,), (" At .eqm.",(a-X),,(0.5+p),,p " atm".):}` i.e., if x moles of `NH_(4)HS` decompose , increase in pressure due to `NH_(3)` = increase in pressure due to `H_(2)S` = p atm . Total pressure at equilibrium ` 0.5 + p+ p = 0.5 + 2 p ` atm ` 0.5 + 2 p = 0.84 " atm" or p=0.17` atm ` :. p_(NH_(3)) = 0.5 + 0.17 = 0.67` atm ` p_(H_(2)S) = 0.17 ` atm ` K_(p) =p_(NH_(3)) xx p_(H_(2)S)` ` =0.67 xx 0.17 = 0.1139`