# What would likely occur if "potassium iodide" were added to "ferric nitrate"?

Mar 11, 2017

$F e {\left(N {O}_{3}\right)}_{3} \left(a q\right) + 3 K I \left(a q\right) r i g h t \le f t h a r p \infty n s 3 K \left(N {O}_{3}\right) \left(a q\right) + F e {I}_{3} \left(a q\right)$

#### Explanation:

This is a type of metathesis reaction, i.e. a partner exchange reaction. Neither of the products are particularly insoluble, and they would remain in solution as the aquated ions, i.e. $F {e}^{3 +}$, ${I}^{-}$ etc.

Additional redox reactions are conceivable, i.e. reduction of ferric to ferrous ion, or oxidation of iodide ion to tri-iodide, i.e. ${I}_{3}^{-}$:

$F {e}^{3 +} + {e}^{-} \rightarrow F {e}^{2 +}$ ${E}^{0} = 0.77 \cdot V$

${I}^{-} \rightarrow \frac{1}{2} {I}_{2} + {e}^{-}$ ${E}^{0} = - 0.54 \cdot V$

$3 {I}^{-} \rightarrow {I}_{3}^{-} + 2 {e}^{-}$ E^(0)=??*V

Oxidation of the iodide anion might indeed drive the ferric ion reduction. The ${E}^{0}$ values show that the reaction is certainly thermodynamically feasible.

In the absence of further information, we invoke the given, so-called $\text{metathesis or partner-exchange reaction}$, which proceeds WITHOUT redox transfer.