`XY_(2)` dissociates `XY_(2)(g) hArr XY(g)+Y(g)`. When the initial pressure of `XY_(2)` is `600` mm Hg, the total equilibrium pressure is `800` mm Hg. Calculate K for the reaction Assuming that the volume of the system remains unchanged.

Options

A. `50.0`
B. `100.0`
C. `166.6`
D. `400.0`

Answer

B

Explanation

`{:(,XY_(2),hArr,XY,+,Y),("Initial",P,,0,,0),("Final",P-x,,x,,x):}`
Initial `P=600` mm Hg, Final `P=800` mm Hg
Total "moles" `prop` final P.
`:. P-x+x+x prop 800`
`600-x+x+xprop 800`
`x=200` mmHg
`K=(x xx x)/(P-x)=(200xx200)/(400)=100 Hg`