Chapter 9: Introduction to Solutions and Aqueous Reactions

9.3 Solution Stoichiometry (307)

• In aqueous reactions, quantities of reactants and products are often specified in terms of volumes and concentration. We can use the volume and concentration of a reactant of a reactant or product to calculate its amount in moles. 
• Volume A==> Amount A (in moles) ==> Amount B (in moles) ==> Volume B

9.4 Types of Aqueous Solutions and Solubility

• When a solid is put into a liquid solvent, the attractive forces that hold the solid together (the solute-solute interactions) compete with the attractive forces between the solvent molecules and the particles that compose the solid (solvent-solute interactions)
• Electrolytes and Non electrolyte Solutions
• A salt solution (Electrolyte) conducts electricity while a sugar solution (Non electrolyte) does not. 
• Salt (ionic) 
• Electrolyte: Substances that dissolve in water to form solutions that conduct electricity.
• Strong Electrolyte: Substances that completely dissociate into ions when they dissolve in water. Strong acids are strong electrolytes. 
• Weak Electrolyte: Does not completely ionize in water. Weak acids are weak electrolytes that conduct electricity weakly. 
• Sugar (molecular)
• Most molecular compounds-with the exception of acids- dissolve in water as intact molecules. Sugar dissolves because the attraction  between sugar molecules and water molecules, overcome the attraction of sugar molecules to each other. 
• Compounds such as sugar that do not dissociate into ions when dissolved in water are nonelectrolytes that do not conduct electricity. 
• Acids (Molecular)
• Ionize to form H+ ions when they dissolve in water. 
• Ex. HCI ionizes into H+ and Cl- when it dissolves in water.  HCI (aq) ==> H+(aq) + Cl- (aq)
• Strong acids completely ionizes in solution. 
• In general, a compound is soluble if it dissolves in water and insoluble if it does not.

9.5 Precipitation Reactions

• Precipitation Reaction: a reaction in which a solid forms upon the mixing of two solutions. 
• However, they do not always occur when two aq solutions are mixed. 
• The key to predicting reactions is understanding that only insoluble compounds form precipitate. Two solutions containing soluble compounds combine and an insoluble compound precipitate. 
• Practice Problems (317)

9.6 Representing Aqueous Reactions: Molecular, Ionic, and Complete Ionic Equations

• Molecular Equation: A chemical equation showing the complete, neutral formulas for every compound in a reaction. 
• Complete Ionic Equation: Chemical equation showing all of the species as they are actually present in solution
• Net Ionic Equation: Equation showing only the species that actually change during the reaction.

9.7 Acid-Base Reactions

9.9 Oxidation-Reduction Reactions