# What is the Ksp and Kf of Zn(H_2O)_6 ?

Mar 26, 2017

Well ${K}_{\text{sp}}$ is unknown..........

#### Explanation:

I think you refer to the zinc ion in water, which we should represent as ${\left[Z n {\left(O {H}_{2}\right)}_{6}\right]}^{2 +}$. Salts such as $Z n C {l}_{2}$ are mighty soluble in water (you'll have to dig for the details), but if we represent its solubility as $S$,

then according to the solubility equation:

$Z n C {l}_{2} \left(s\right) + \text{excess} {H}_{2} O r i g h t \le f t h a r p \infty n s Z {n}^{2 +} + 2 C {l}^{-}$

And so ${K}_{\text{sp}} = \left[Z {n}^{2 +}\right] {\left[C {l}^{-}\right]}^{2}$

And reasonably, we can equate the solubility of the salt, $S$, with $\left[Z {n}^{2 +}\right]$. Do you agree?

And so, finally, we write, ${K}_{\text{sp}} = S \times {\left(2 S\right)}^{2} = 4 {S}^{3}$.

${K}_{\text{f}} \left(Z {n}^{2 +} \left(a q\right)\right)$ is a trickier proposition.