Chapter 4 - More Stoichiometry

• Solution - homogeneous mixture.
• Molarity
• ratio of solute to solution.
• symbol M
• conversion factor
• Dilution
• addition of more solvent.
• C1V1 = C2V2
• volumes can be any unit if they are the same.
• volumes are volumes of solution.

• Electrolytes
• water d/n conduct electricity very well.
• electrolytes form ions in solution
• Strong electrolytes
• Strong acids (HCl, HBr, HI, HNO3, HClO3, HClO4, H2SO4)
• Strong bases (MOH, Ba(OH)2, Sr(OH)2, and Ca(OH)2)
• Soluble ionic compounds (salts) (Table 4.3)
• SOLUBLE EXCEPT:
• Nitrate, Acetate - NO EXCEPTIONS
• Chloride - EXCEPT Ag+, Pb2+, Hg22+
• Br-, I- add Hg2+
• Sulfate - EXCEPT Ca2+, Sr2+, Ba2+, Pb2+, Hg22+, Ag+
• INSOLUBLE EXCEPT:
• Sulfides - IA, IIA, and NH4+
• Carbonates, Phosphates - IA and NH4+
• Hydroxides - IA, Ca2+, Sr2+, Ba2+
• Weak electrolytes
• weak acids (typically H written as the first element)
• weak bases (nitrogen (NH3))
• establish chemical equilibrium w/molecules and ions
• HA H+ + A-
• Neutralization reaction

• Ionic Equations
• molecular equation
• total ionic equation
• write strong electrolytes as ions
• DO NOT CONFUSE SOLUBLE WITH STRONG ELECTROLYTE
• covalent compounds can be soluble w/out forming ions!!!!!
• net ionic equation
• cancel spectator ions
• must have same formula and charge.
• metathesis rxn (double displacement)
• form precipitate
• form soluble weak or nonelectrolyte
• form a gas

• Reaction of metals
• oxidation-reduction
• single replacement reactions
• activity series (4.5)

• titrations
• standard solution - solution for which the concentration of the solute is known very accurately.
• equivalence point - stoichiometrically equivalent amounts of reactants (neither reactant is the limiting reactant, or both reactants are the limiting reactant)
• use M as a conversion factor.

Learning goals:

1. Calculate molarity, solution volume, or moles of solute given any two of these quantities.

2. Calculate the volume of a more concentrated solution that must be diluted to obtain a given quantity of a more dilute solution.

3. Identify substances as acids, bases, or salts.

4. Predict whether a substance is a nonelectrolyte, a weak electrolyte, or a strong electrolyte from its formula.

5. Predict the ions formed by electrolytes when they dissociate or ionize.

6. Identify the spectator ions and write the net ionic equations for solution reactions starting with their molecular equations.

7. Predict the products of metathesis reactions and write balanced chemical equations for them.

8. Identify the driving force for any metathesis reaction.

9. Use solubility rules to predict whether a precipitate will form when electrolytes are mixed.

10. Use the activity series to predict whether a reaction will occur when a metal is added to an aqueous solution of either a metal salt or an acid; write the balanced chemical molecular and net ionic equations for the reaction.

11. Calculate the concentration or mass of solute in a sample from titration data.