Chapter 12.3, Problem 25PP

Interpretation Introduction

Interpretation:

Determine whether a solid forms when solutions containing the following ionic compounds are mixed. If so, write the ionic equation and the net ionic equation.

1. KCl (aq) and Na₂S (aq)
2. AgNO₃ (aq) and K₂S (aq)
3. CaCl₂ (aq) and Na₂SO₄ (aq)
4. CuCl₂ (aq) and Li₃PO₄ (aq).

Concept introduction:

Ionic compounds are dissolved in water. Because they contain soluble anion and cation will dissolve in water.

Solubility rules for ionic compounds in water

An ionic compound is soluble in water if it contains one of the following
Positive ions	Li+, Na+, K+, Rb+, Cs+ and NH4+
Negative ions	${\text{NO}}_{\text{3}}^{\text{-}}{\text{,C}}_{\text{2}}{\text{H}}_{\text{3}}{\text{O}}_{\text{2}}^{\text{-}}$
	Cl-, Br-,I- except when combined with Ag+, Pb2+ or ${\text{Hg}}_{\text{2}}^{\text{2+}}$ ${\text{SO}}_{\text{4}}^{\text{2-}}$ except when combined with Ba2+, pb2+,Ca2+,Sr2+,Sr2+ or ${\text{Hg}}_{\text{2}}^{\text{2+}}$

Some ionic compounds do not have the above ions. Those are insoluble compounds.

We can also use solubility rules for solid compounds to predict the solubility.

Solutions containing soluble reactants are mixed together to form precipitate.

To write an equation for the formation of an insoluble ionic compound is as follows.

• Write the ions of the reactants.
• Write the combination of ions and determine if any are soluble.
• Write the ionic equation including any solid.
• Write the net equation.