Chapter 17, Problem 17.127SP

Interpretation Introduction

Interpretation:

The compound that will precipitate when $\text{Ba}{\left(\text{OH}\right)}_{\text{2}}$ and ${\text{Fe}}_2{\left({\text{SO}}_4\right)}_3$ are mixed is to be identified.

Concept introduction:

Solubility product is equilibrium constant for reactions that occur when an ionic compound is dissolved to produce ions. It is denoted by $K_{\text{sp}}$. Consider ${\text{A}}_x{\text{B}}_y$ an ionic compound. Its dissociation occurs as:

${\text{A}}_x{\text{B}}_y\rightleftharpoons x{\text{A}}^{y+}+y{\text{A}}^{x-}$

The expression for its $K_{\text{sp}}$ is as follows:

$K_{\text{sp}}={\left[{\text{A}}^{y+}\right]}^x{\left[{\text{B}}^{x-}\right]}^y$

A precipitate of an ionic compound will form when solution that contain consttuent ion are mixed. The precipitation depends on value of ion product (IP). The IP is defined in the same way as $K_{\text{sp}}$. Also, the concentrations in expression for IP are initial concentration at time ( t ) and not equilibrium concentrations. Consider an ionic compound ${\text{A}}_x{\text{B}}_y$. Its dissociation occurs as follows:

${\text{A}}_x{\text{B}}_y\rightleftharpoons x{\text{A}}^{y+}+y{\text{A}}^{x-}$

The expression for its IP is as follows:

$\text{IP}={\left[{\text{A}}^{y+}\right]}_t{}^x{\left[{\text{B}}^{x-}\right]}_t{}^y$