CHEM 5013
REVIEW SHEET
EXAM #4
Chapter Four – Stoichiometry
 (4.3) Limiting Reactants (Reagents)
o What is a limiting reactant?
o Using stoichiometry (molar masses and molar ratios) to determine the limiting
reactant for a BALANCED chemical equation – like Aspirin Lab
Chapter Five – Gases
 Basic properties of gases (Definition of a gas)
 Pressure
o Definition of Pressure = Force per unit area
o How does altitude affect pressure?
o Converting between various units of pressure – Conversion factors will be
provided
 History and Application of the Gas Law
o Empirical Gas Laws (KNOW THESE!!!) – Recall that all temperatures MUST
be converted to Kelvin units first!!!
 Boyle’s Law: P1 V1 = P2 V2 (at constant T and constant moles)

Charles’s Law: V1/T1 = V2/T2 (at constant P and constant moles)

Combined Gas Law: P1V1/T1 = P2V2/T2 (for a given # moles of gas)

Avogadro’s Law:
Vm=specific constant = 22.41 L/mol at STP
 STP = Standard temperature and pressure = 1 atm and 0°C (273K)
 History and Applications of the Gas Law
o The Ideal Gas Law
PV=nRT (where n = Number of moles of GAS) – THIS
WILL NOT BE GIVEN TO YOU FOR THE EXAM, YOU MUST MEMORIZE IT!
 Stoichiometry of Reactions Involving Gases
o Combining Gas Law with Stoichiometry fundamentals from Chapter 4
o Make sure you understand the calculations from the Ideal Gas Law Lab!
 Determining the density of a gas. – One approach is to assume the volume is one
liter, use Ideal gas Law to calculate the moles of gas per liter, then convert moles
to grams per liter = Density.
 Dalton’s Law of Partial Pressures; Gas Mixtures
PT=PA+PB+…
Also understand that each gas in a mixture individually follows the Ideal Gas Law.
Chapter Thirteen – Electrochemistry
 Definitions of Oxidation (losing electrons, oxidation number rises) and Reduction
(gaining electrons, oxidation number is lowered)
 Calculating Oxidation numbers for a species
 Definitions of Oxidizing Agent and Reducing Agent
 Be able to write oxidation half-reactions and reduction half-reactions
 Understand the basic construction of a Galvanic cell including the parts (Salt Bridge,
Anode=oxidation side and Cathode=reduction side)
 Write out cell notation for a galvanic cell given a reaction and write out a reaction
given the cell notation
 Cell Potentials – understand how to use the provided Table of Reduction Potentials
and how to calculate a Cell Potential for a galvanic cell
(E0cell = E0red – E0ox)
 Batteries – Define Primary and Secondary Cells and provide examples of each
 Calculate the amount of metal plated in an electrolysis reaction using stoichiometry
– Faraday’s Constant value will be provided.
 Understand the basic concepts of corrosion, galvanizing and cathodic protection
Rules for Exam
1. You obviously will need your calculators.
2. You will be provided with a reference sheet identical to the one given to you in class
as well as a Periodic Table.
3. No other outside sources or information allowed.
Advice
Study the suggested problems on the website and the quizzes – many problems will
be similar to the problems on these.
Valuable Hint (Reminder!!!):
Chemistry is a subject which builds upon itself. You will need to use information
that you learned for Exams 1, 2, and 3 in order to solve some problems on Exam 4.
Specifically, it is assumed that you know how to provide correct chemical formulas
given the name of a compound and that you can provide the name of a compound given
the chemical formula. It is also assumed that you will know how to convert from one
unit to another (ex. mL to cm3 or mL to L). Also, know the density formula!!!
Example: You should be able to provide a correct formula for calcium carbonate
(CaCO3)