What is the ratio of uncomplexed to complexed to complexed `Zn^(2+)` ion in a solution that is `10 M "in" NH_(3) ` . If the stability constant of `[Zn(NH_(3))_(4)]^(2+)` is `3xx10^(9)`?

Options

A. `3.3xx10^(-9)`
B. `3.3xx10^(-11)`
C. `3.3xx10^(-14)`
D. `3xx10^(-13)`

Answer

C

Explanation

`Zn^(2+)+4NH_(3)iff[Zn(NH_(3))_(4)]^(2+)`
`K_(f)=([Zn(NH_(3))_(4)]^(2+))/([Zn^(2+)][NH_(3)]^(4))implies([Zn(NH_(3))_(4)]^(2+))/([Zn^(2+)])=K_(f)[NH_(3)]^(4)`
`=3xx10^(9)xx10^(4)=3xx10^(13)`.
`implies ([Zn^(2+)])/([Zn(NH_(5))_(4)]^(2+))=(1)/(3xx10^(-13))=3.3xx10^(-14)`