Exam 2 review

What are the three types of cubic unit cells found in crystal lattices?
How many net atoms are found in the cubic unit cells?
Be able to calculate density of a substance given its unit cell type (primitive, FCC, BCC) and the unit cell dimensions.
What is the difference between molecular, ionic, covalent-network and metallic solids?
Practice problems: 11.61

What types of intermolecular forces operate between solute and solvent particles in a solution?
Does the solution process involve chemical or physical changes?
What factors (in terms of intermolecular attractive forces) determine whether or not a solution will form?
What steps in solution formation are endothermic? Which are exothermic?
What role does disorder play in solution formation?
How does one calculate the mass % of a component in a solution?
How do we express the concentration of a very dilute solution in parts per million (ppm)?
How do we calculate the mol fraction of a component in a solution?
How do we calculate the molarity of a solution? Be able to calculate moles given molarity and volume, volume given molarity and moles, etc.
How do we calculate the molality of a solution?
Why do we use molality?
What are colligative properties?
How does a nonvolatile solute lower the vapor pressure of the solvent above a solution?
How do we differentiate between molecular and ionic solutes when we consider colligative properties?
What is a 1:2 ionic compound? A 1:3 ionic compound?
How is Raoult's Law used to calculate the vapor pressure above a solution?
How is the boiling point elevation/freeze point depression calculated for a solution? What must be taken into account if the solute is ionic?
How do we gauge (in a qualitative sense) the effect on boiling point/freeze point of a solution by looking at the nature of the solute (i.e. electrolyte/nonelectrolyte solute)?

Practice problems: 13.3, 13.5, 13.11, 13.25, 13.29, 13.31, 13.45, 13.47, 13.51, 13.53

How do we calculate the formula weight (or molecular weight) of a substance?
What is Avogadro's Number?
What does Avogadro's Number represent? What are its units?
How do we use Avogadro's Number to convert atoms or molecules to moles?
What is meant by molar mass? How is this quantity calculated? What are its units?
How do we use the molar mass to convert between grams and moles and vice versa?
Be able to convert a gram amount of a substance to number of atoms of a particular type.
What does the empirical formula for a substance tell us?
How is the empirical formula of a compound related to the molecular formula?
How do we calculate empirical formulas given mass percentages of the elements in a compound?
Given the empirical formula and the true molecular weight of a compound, how do we find the molecular formula?
How do we convert moles of one substance in a reaction to moles of any other substance in a reaction?
Given the gram masses of two reactants in a reaction, how do we identify the limiting reactant?
Given the limiting reactant in a reaction, how do we calculate the amount of excess reactant remaining at the end of the reaction?
How do we calculate the theoretical yield of a reaction?
How do we calculate the per cent yield of a reaction?
Work the following problems for practice: 3.15, 3.27, 3.29, 3.33, 3.45, 3.55, 3.67, 3.69,

Given any two of the following: moles, volume, or molarity, be able to calculate the third.
What is a titration?
What is the definition of the equivalence point in a titration?
Be able to work solution stoichiometry problems! Review writing balanced chemical equations for double- displacement and neutralization reactions, and review the general solubility rules!
Suggested problems: 4.51, 4.53, 4.55, 4.59, 4.67, 4.69

Remember - 5 extra credit points will be given for a note card turned in before the exam!

Send questions, comments, etc to chapman@sou.edu

doug chapman chapman@sou.edu 2/27/08