Solubility's of Solid Compounds

Solubility's of Solid CompoundsSolubilities of Solids increase with larger Surface AreaRemember, greater surface area = faster dissolvingThis is because dissolution can only occur at the surface of solid particles where the solvent can touch

Solubilities of Solids Generally Increase with TemperatureAnother way to increase the solubility of solids is to increase the temperatureThis is effective because, generally, solvent molecules at a higher temperature have more kinetic energy and can dissolve more.THE SOLUBILITY OF A SUBSTANCE AT A GIVEN TEMPERATURE IS AMOUNT OF SOLUTE PER AMOUNT OF SOLVENTAgitation or Stirring can increase solubilityStirring a solution (agitating it) increases the solubility of solution by increasing the rate of dissolution In Summary:There are three ways to increase the rate of dissolution of a solid in solution (e.g. sugar in a cup of tea)Increase the surface area (by crushing the sugar)Increasing the temperatureStirring or agitating the solutionSolubility of Ionic Solids: DissociationDissolving of an ionic compound involves the separation of ions from the lattice into individual dissolved ions. This process is called Dissociation. Two ions are produced for each formula unit of a solid.

Dissociation Equation:NaCl Na+ + Cl-An equation for the dissociation of an ionic solid shows the solid on the left side and aqueous ions on the right side

Solubility and Ionic SubstancesIn order to dissolve ionic substances, the strong electronegative bonds between ions must be brokenPolar solvents are attracted to the ions If the force between an ion and a solvent is stronger than of attraction between the ions themselves, the solid will dissolve

Solutions at EquilibriumIn saturated solutions, dynamic equilibrium exists between undissolved solids and ionic species in solution.It is considered dynamic because solute particles are dissolving and recrystallizing at the same rate. Solubility RulesRemember that when combining two aqueous solutions of ionic compounds. We must write the equation for a precipitation reaction

We must check the solubility rules to see if there is a insoluble compound formedSolubility Rules: ExampleKOH and NH4Cl Write an equation:KOH + NH4Cl KCl + NH4OH (notice they have swapped partners)We then check for insoluble compoundsKCl: SOLUBLE (chlorides are soluble except those of Ag+, Pb2+ and Hg22+)NH4OH: SOLUBLE (hydroxides are insoluble except those of group 1 and NH4+ ) PLEASE NOTE THAT NH4+ COMPOUNDS ARE ALL SOLUBLESolubility Rules: ExampleNH4Cl and AgNO3 Write an equation:AgNO3 + NH4Cl AgCl + NH4NO3 (notice they have swapped partners)We then check for insoluble compoundsAgCl: NOT SOLUBLE (chlorides are soluble except those of Ag+, Pb2+ and Hg22+)NH4NO3: SOLUBLE (All nitrates are soluble)