General Chemistry II Student Competencies

Chemistry: The Central Science, Brown, Lemay, and Bursten, 2000.

Chapter 14	Chapter 15	Chapter 16	Chapter 17
Chapter 18	Chapter 19	Chapter 20

Chapter 14 Student competencies

Upon completion of this chapter, students should be able to:

Use kinetic-molecular theory to explain how reactions occur. Be able to explain the underlying reason for why concentration and temperature changes affect reaction rates.
Understand the main factors that control the rate of a reaction.
Understand exactly what “reaction rate” means and be able to calculate the rate of a reaction when given data showing concentrations at various times.
Be able to use reaction stoichiometry to write the rate of a reaction in terms of how each product or reactant concentration changes with time
Given a set of data showing reaction rates for various combinations of concentrations, calculate the rate law and the rate constant.
Be able the write the rate law expression. Understand the units associated with rate, what reaction order is, and how the units of the rate constant k vary with reaction order.
Understand and be able to use the Arrhenius expression:

Be able to show how the Arrhenius equation accounts for collision frequency and orientation factors
Know how to determine the fraction of molecules with sufficient energy to react at a given temperature for a given activation energy.
Demonstrate an understanding of how to graphically determine the activation energy for a given reaction.
Given rate constants at multiple temperatures, know how to calculate the activation energy for the reaction. From the activation energy and rate constant at one temperature, be able to predict the rate constant at any other temperature.

Understand first order reactions:

Be able to write the rate law for such a reaction
Know and be able to use the expression for how concentration changes with time in a first order reaction
Know and be able to use the expression that relates the half-life with the rate constant for a first order reaction.
Explain graphically what parameters to plot to show if a reaction is a first order process.

Understand second order reactions:

Be able to write the rate law for such a reaction
Know and be able to use the expression for how concentration changes with time in a second order reaction
Know and be able to use the expression that relates the half-life with the rate constant for a second order reaction.
Explain graphically what parameters to plot to show if a reaction is a second order process.

Understand how reaction rate varies with temperature and the two underlying reasons for this. Use a kinetic molecular distribution diagram and an energy reaction coordinate diagram to explain this.
Understand and be able to depict the change in enthalpy, the activated complex, and the activation energies for a forward and reverse reaction on an energy reaction coordinate diagram.
Explain what is meant by a reaction mechanism; be able to write the rate laws for elementary steps and to clearly outline the significance of the rate-determining step. Understand the terminology associated with reaction mechanisms.
Given that a specific step in the reaction mechanism is identified as the slowest step, predict the rate law associated with this mechanism.
Use an energy diagram to explain how a catalyst affects reaction rates.
Explain how heterogeneous and homogeneous catalysts work.
Understand the role of enzymes in living systems to include:

The lock-and-key model of enzyme action and an understanding of the active site.
The specific types of interactions that occur between substrates and enzymes
The importance of enzyme inhibition and turnover number and how these are related to toxic effects and activation energies respectively.

Identify the three major pollutants from automobiles and outline the reactions that each undergo in catalytic converters.

Chapter15 Student competencies

Upon completion of this chapter, students should be able to:

Relate forward and reverse reaction rates to equilibria and to equilibrium constants.
Know what is meant by the Law of Mass Action. For both homogeneous and heterogeneous reactions, be able to write the expression for the equilibrium constants K_c and K_p. Relate the value of the equilibrium constant to the position of equilibrium.
Given concentrations or pressures, determine the value of the equilibrium constant. Be able to relate K_c and K_p.
Understand the factors that change the equilibrium constant.
Know what is meant by the reaction quotient Q. Given a set of concentrations and the equilibrium constant, determine whether a particular reaction is at equilibrium. If it is not, predict which way it would spontaneously shift to reach equilibrium.
Given a set of initial concentrations and the equilibrium constant, calculate the equilibrium concentrations.
Understand Le Chatelier's principle and be able to explicitly state it. Understand how equilibria respond to pressure, temperature, and concentration changes. Be able to explain why in terms of the relative effects on the forward and reverse reaction rates.
Understand how a catalyst affects equilibria.

Chapter 16 Student competencies

Upon completion of this chapter, students should be able to:

Be able to define and identify Arrhenius, Bronsted-Lowry, and Lewis acids and bases.
Given the pH, pOH, [OH^-], or [H₃O⁺}; be able to quickly calculate the other three to the correct number of significant figures.
Understand what is meant by conjugate acid-base pairs and how the strength of one is related to the weakness of the other.
Understand the K_w equilibrium and explain what the pH scale represents.
Be able to identify the strong acids and bases and to calculate the pH, or pOH for a given concentration.
Relate the K_aof an acid to the K_b of its conjugate base.
From the K_a and an initial concentration, be able to determine the pH of a weak acid solution. From the K_b and an initial concentration, be able to determine the pOH of a weak base solution.
Be able to identify weak acids and weak bases and to write the reaction of each with water.
Show the reactions that occur for polyprotic acids.
Be able to identify a species that can act as an acid or as a base; be able to determine whether a solution of this species would be acidic basic, or neutral.
Understand the acid-base properties of a salt solution. Given a salt, be able to write the hydrolysis reactions of each of its ions (cation and anion) with water. Use these to predict whether the reaction would be acidic, basic, or neutral.
Understand the three main factors (bond polarity, bond strength, and stability of conjugate base anion) that affect acid strength; use these to rank order a series of structures in terms of their acidity or basicity.
Understand the relative acidity of oxyacids with differing number of oxygen atoms.
Be familiar with the structure of carboxylic acids and understand why they are acidic.
Understand and be able to diagram how metal ions not in Groups I or II react with water. Relate acidity of metal ions to charge and size. Discuss acidity of these metal ions in terms of Lewis acids and bases.
Be able to determine the percent ionization for a weak acid or base solution.

Chapter 17 Student competencies

Know what is meant by a buffer and understand the pH range over which buffers are typically considered to be effective.
Know the Henderson-Hasselbalch equation; demonstrate an understanding of how to use it to prepare buffers and to calculate the pH of a given solution of an acid/conjugate base pair. Relate the pH of a buffer system to the relative concentrations of the acid/conjugate base pair.
For a given buffer system, write the reactions that would occur with the addition of a strong base and with the addition of a strong acid.
Understand how to carry out an acid-base titration calculation.
For the titration of a weak base with a strong acid; outline what type of solution remains at the equivalence point. Be able to do the same for the titration of a weak acid with a strong base.
For a given ionic salt that has low solubility in water, demonstrate an understanding of solubility equilibria and of K_sp.
For a given K_sp, calculate the solubility for the salt. For a given solubility (given in M or in mg/dL), know how to determine K_sp.
Determine the solubility of a substance in a solution that already contains one of the ions present in the salt.
For salts with basic anions, predict the effect of pH on solubility; demonstrate an understanding of the underlying reasons for this using all appropriate equilibria and Le Chatelier's principle.
Understand and diagram what a complex ion is; identify the Lewis acid and base. Know the equilibria for complex ion formation. Discuss how complexes affect the solubility of metal ions by showing appropriate equilibria. Understand the role of complex ions in the human body..
For partially soluble salts with non Group I or II metal ions, predict the effect of ligand concentrations (e.g. NH₃) on solubility. Show the underlying reasons for this using all appropriate equilibria and Le Chatelier's principle.

Chapter 18 Student competencies

Understand photodecomposition and photoionization processes. Use molar bond energies to determine maximum wavelengths for photodecomposition.
Know the principle components of the atmosphere and their relative abundances.
Understand how ozone concentration changes with altitude; use rate law chemical kinetics to explain this profile.
Know what wavelengths are associated with visible, UV-A, UV-B, and UV-C radiation. Explain how transparent or opaque the atmosphere is to each of these regions. Identify atmospheric components that absorb light in these regions.
Understand what is meant by catalyzed ozone destruction. Write an appropriate set of reactions for this process and identify the catalyst.
Outline the theory proposed by Roland and Molina during the early 1970's concerning stratospheric ozone.
Explain what occurs to the ozone over the South Pole each year; outline the specific set of reactions and the underlying reasons for the occurrence of this phenomenon.
Discuss the adverse environmental consequences of lower stratospheric ozone levels.
Use appropriate chemical reactions to explain the concerns that surfaced during the 1970's associated with the potentially adverse impacts of large-scale use of supersonic transport planes in the stratosphere.
Identify the three pollutants emitted by internal combustion engines. Outline the reasons for each of these emissions and the adverse environmental impacts of each of these pollutants. Explain the processes that occur in catalytic convertors to minimize the emissions of these.
Explain what pollutant is emitted when air is heated to high temperatures. Use LeChatlier's principle to explain why this occurs.
The Charlotte-Rock Hill region is among the ten most polluted urban areas in the United States in terms of photochemical smog. Outline the set of reactions that occurs during the formation of smog; identifiy the specific primary source of precursors. Recommend viable control strategies to effectively address this issue.
Explain the underlying basis for the greenhouse effect. Identify the specific molecular property that makes an atmospheric component a greenhouse gas. Provide sound technical recommendations on actions that could be taken to address this issue. Understand the progress being made.
Outline the specific concerns associated with particulates and air quality. Understand the types of particulates involved, the makeup of these, and the adverse human health effects of these.
Outline the sources of acid rain and the chemical reactions used in coal-fired power plants in scrubbers.
Understand the biochemical mechanism of action of nerve agents and organophosphorus pesticides. Identify the functionality on nerve agents GB, GD, and VX that affects the time before irreversible enzyme inhibition occurs. Explain the mechanism of action for PB tablets administered to American military during Desert Storm and which particular nerve agent threat generated the need for these tablets.
Compare the intermolecular forces and vapor pressures associated with the nerve agents GB and VX.
Identify the two primary routes of entry--how humans would be exposed--to nerve agents.
Explain why chlorinated pesticides such as DDT have been replaced with organophosphorus pesticides that are much more toxic to humans.

Chapter 19 Student competencies

Understand all the concepts from the thermochemistry chapter covered during first semester.
Understand the first and second law of thermodynamics; solve problems associated with them.
Be able to calculate the enthalpy change for a reaction using enthalpies of formation, bond energies, calorimetry, or Hess's Law.
For a given reaction and without use of themodynamic tables, predict whether enthalpy and entropy increases or decreases. Be able to apply this to predict the conditions under which reactions would be spontaneous.
Use thermodynamic tables to calculate equilibrium constants, boiling points, melting points, and changes in enthalpy, entropy and free energy.
Use the second law of thermodynamics to clearly explain why most of the heat released from burning coal at power plants is not transformed into electricity. Be able to describe what is done with this heat.
Relate equilibrium constants to the magnitude of the free energy change. .

Chapter 20 Student competencies

Use the standard reduction potential table to predict which reactions occur spontaneously.
Diagram an electrochemical cell, identifying the cathode, anode, what reactions occur at each, and what voltage would be predicted under standard conditions.
Explain the relationship between ion concentration gradients and voltage potential differences across a cell membrane. Use this information to explain how a nerve impulse is transmitted across a synapse.
Write half reactions and identify each species.
Relate voltage differences with concentrations. Be able to use the Nernst equation effectively.
Outline what is meant by a fuel cell and explain why these are often in the news. Outline the technical issues that must be resolved before these can be widely utilized. Provide realistic assessments of the feasibility of these.
Understand why magnesium rods are connected at routine intervals to oil pipelines. Show the specific reactions involved and why these would be spontaneous.
Conduct quantitative calculations for electrolytic processes.