`I_(2)+I^(ɵ)hArrI_(3)^(ɵ)`
This reaction is set-up in aqueous medium. We start with `1` mol of `I_(2)` and `0.5` mol of `I^(ɵ)` in `1 L` flask. After equilibrium reached, excess of `AgNO_(3)` gave `0.25` mol of yellow precipitate. Equilibrium constant is

Options

A. 1.33
B. 2.66
C. 2
D. 3

Answer

A

Explanation

`{:(,I_(2),+,I^(-),hArr,I_(3)^(-)),("Initial",1M,,0.5M,,-),("At eqm,. " ,(1-x)M,,0.5M,,x "mol"):}`
Moles of `AgI=` Moles of `I^(-)` in solution
`:. [I^(-)]_("eqn")=0.25M`
`0.5-x=0.2:. x=0.25`
`K=(x)/((1-x)(0.5-x))`
`=(0.25)/(0.75xx0.25)=1.33`