Learning objectives for Chemistry 371 - Chemistry of the Environment
Simon Fraser University - 1993
Please note: this course has now been split into two. The first course,
officially on the aquatic environment, also covers the geochemical
topics.
The second course is on the atmospheric environment and will also
cover environmental radioactivity. As a result, the topics listed in
Section 11 (Chemistry of the atmosphere) are likely to be expanded.
This list is a text export of the original FrameMaker document.
For further information, contact Steve Lower, Dept of Chemistry,
Simon Fraser University, Burnaby BC V5A 1S6 Canada
(lower@sfu.ca)
*************************************************************************
********
1 Survey of Environmental Geobiochemistry
1.
Describe the general structure of the earth; i.e., its division
into core, mantle, and crust. Comment on the physical and chemical
distinctions
between these regions.
2.
Describe the general nature of the continental and oceanic crust,
and explain the role of plate tectonics in the evolution of the earth.
3.
Summarize the evolution of the earth in terms its accretion, and
the various stages of differenti- ation leading to the core, mantle, and
crust,
and the formation of the primitive atmosphere.
4.
Describe the major processes involved in weathering of rocks and
sediments.
5.
Describe the general nature of soils.
6.
Describe the major factors influencing the thermal balance of the
earth, and explain the
7.
mechanism of the Ògreenhouse effectÓ.
8.
Describe the evolution of the earthÕs atmosphere.
9.
Describe the major factors affecting the distribution of carbonate
sediments on the ocean floor.
10.
Summarize the chemistry of the biosphere in terms of the major
reactions: fermentation, respiration, and photosynthesis.
11.
State the major kinds of evidence that are used to infer the
biogenic origin of substances found in sedimentary deposits.
12.
Describe the various stages in the chemical origin and evolution
of life, and its effect on the composition of the atmosphere. Comment on
the
significance of MillerÕs 1953 experiment.
13.
State the general tenets of the ÒGaia hypothesisÓ.
*************************************************************************
********
2 Thermodynamics and kinetics
1.
Define enthalpy and explain its physical significance.
2.
Explain, qualitatively, why the entropy of a system should depend
on such factors as bond strengths, the number of particles and their
complexity, and on the temperature.
3.
Define the standard Gibbs free energy G°, and state its physical
significance.
4.
Define chemical potential and explain its meaning.
5.
Define the activity and explain its meaning.
6.
Explain the difference between DG and DG°.
7.
Justify the statement that Òno reaction in homogeneous solution can
be truly completeÓ.
8.
Given values of Q and K, state how the reaction composition relates
to the equilibrium composition.
9.
Given basic thermodynamic data, indicate whether an equilibrium
constant will increase or decrease as the pressure or temperature is
changed.
10.
Explain what is meant by a diffusion-controlled reaction, and
state the effect that this condition would have on the observed
kinetics.
*************************************************************************
********
3 Acid-base theory of aqueous systems
1.
Define the pH, and explain why the pH of a neutral aqueous solution
is not always 7.0.
2.
Write expressions for Ka and Kb for an acid-base system, and derive
the relation between them.
3.
Construct a proton free energy diagram for a set of conjugate
species whose pKÕs are given, and explain the significance and use of
this
diagram.
4.
Write charge-balance and mass-balance expressions for a given
system of acids and bases.
5.
Define the dissociation fractions a0 and a1.
6.
Define the quantities ANC and BNC.
7.
Derive an approximate equation relating the [H+] of a solution to
the nominal concentrations of the conjugate acid-base species.
8.
Construct a logarithmic concentration - pH diagram for a given
acid-base system, and use it to sketch a titration curve for the system,
specifying the pH at the beginning and equivalence points.
*************************************************************************
********
4 Carbon dioxide and carbonates in natural waters
1.
Describe the general nature of the carbon cycle as it relates to
the atmosphere and hydrosphere.
2.
Explain the difference between ÒopenÓ and ÒclosedÓ systems
involving carbonate species, and indicate the major chemical
consequences of
changing from one to another.
3.
Write charge balance and proton conditions for solutions of H2CO3,
NaHCO3, and of Na2CO3 in pure water.
4.
Interpret titration data to obtain values for the total alkalinity
and acidity, the carbonate acidity, CO2 acidity, caustic alkalinity and
mineral acidity of a sample of a natural water.
5.
Explain how limestone caves are formed from groundwater.
6.
Predict the effects of biological activity (respiration and
photosynthesis) on the alkalinity, acidity, and pH of a natural water.
*************************************************************************
********
5 Metal ions in solution
1.
Explain what is meant by nucleation in reference to the formation
of precipitates.
2.
Construct and use a logarithmic concentration diagram for a set of
cations with a common anion.
3.
Explain why the solubilities of salts of weak acids and bases are
dependent on the pH, and derive a conditional solubility product
expression.
Estimate the pH range in which the solubility of such a system would be
independent of the pH.
4.
Discuss the effect of H2CO3 on the ÒcorrosivenessÓ of groundwater
on calcite, and explain how this affects the formation of limestone
caves.
5.
Explain the distinction between these types of complex: ion-pair,
coordination, polynuclear.
6.
Describe the nature of humic substances, and their occurrence and
effects in natural waters.
7.
Explain what is meant by the electric double layer, and indicate
how electrokinetic phenomena come about.
8.
Explain what is meant by the zpc of a surface.
9.
Define a colloid, and explain what factors affect the stability of
colloidal dispersions.
10.
Describe the general structure of a clay, and explain how some of
the major properties of clays come about.
*************************************************************************
********
6 Redox equilibria in natural water
1.
Define what is meant by Òstandard electrode potentialÓ of a half
reaction, and relate this quantity to DG°.
2.
Interpret a Latimer diagram for an element in acidic or basic
solution.
3.
Write the Nernst equation for a given electrode reaction.
4.
Define pE and pE°.
5.
Construct or interpret a Òfree energy diagramÓ in which electron
donor and acceptor states are arranged on a pE° scale.
6.
Explain the role of water in limiting the thermodynamic stability
of a oxidizing or reducing solute.
7.
Construct or interpret a log-C vs. pE diagram for an element.
8.
Define oxidizing-reducing capacity.
9.
Interpret a pE vs. pH diagram for an element.
10.
Describe the major factors affecting the pE of the environment,
and the influence of biological activity on localized pEÕs.
*************************************************************************
********
7 Movement of chemicals in the environment
1.
Define: distribution coefficient, partition coefficient, HenryÕs
law, octanol-water partition coef- ficient.
2.
Discuss the general approaches for estimating partition behavior on
the basis of molecular parameters such as fragment constants or
connectivity.
3.
Discuss the basic ideas of the compartment model as applied to
aquatic environments; define accumulative and non-accumulative
reservoirs and
turnover time.
4.
Explain the meaning of the fugacity capacity of an environmental
compartment and give examples of its use.
5.
Discuss the factors influencing the kinetics of transport across
the air-water interface, and describe the basic idea of the two-layer
reisistance model.
6.
Explain the oxygen sag curve relating to the kinetics of
reoxygenation in streams. Discuss the factors affecting the features of
the
sag curve.
*************************************************************************
********
8 Biogeochemical cycles of the major elements
Describe the principal features of the cycles of carbon, oxygen,
nitrogen,
sulfur and phos- phorus. For each of these elements, you should know the
principal chemical forms in each of the major environmental
compartments, the
mechanisms of transport between the com- partments, and what
anthropogenic
inputs have had significant effects on the cycle.
*************************************************************************
********
9 Water: supply, treatment and pollution
1.
Outline the major steps involved in the treatment of municipal
drinking water, prior to its disin- fection.
2.
Summarize the major methods of disinfecting drinking water, and
give the strengths and weak- nesses of each.
3.
Define the terms BOD, COD, TOC, and SS.
4.
Describe the objectives and general methods of primary, secondary
and tertiary sewage treat- ment.
5.
Discuss the relative merits of aerobic and anaerobic treatment of
waste.
6.
Describe the problems and methods associated with the disposal of
sewage sludge.
7.
Explain what is meant by the term eutrophication as applied to
natural waters. What are the major sources of artificially-induced
eutrophication?
8.
Explain the process of seasonal overturn in a lake.
9.
Define bioconcentration and biomagnification, and explain how these
affect the various trophic levels of a food chain.
10.
Describe the dynamics of the oxygen sag curve; state the major
variables and their effects.
*************************************************************************
********
10 Toxic substances in the environment
1.
For each of the heavy metals mercury, cadmium, and lead, list the
major environmental sources, state the major chemical species involved,
and
summarize the problems that they cause.
2.
List the other principal classes of toxic pollutants, and summarize
their sources, occurrence and control.
3.
Summarize the environmental problems associated with the major
British Columbia industries such as mining and smelting, pulp and paper,
and
chloralkali production.
*************************************************************************
********
11 The atmosphere
1.
Describe the general structure of the atmosphere and characterize
its component parts.
2.
Explain the origin and significance of temperature inversions.
3.
Outline the principal features of the photochemistry of oxygen and
of ozone in the upper atmosphere.
4.
Show how NO can act as a homogeneous catalyst for the destruction
of ozone. What are the natural and anthropogenic sources of NO?
5.
List the major sources and sinks for atmospheric CO2, CO, and
hydrocarbons including CH4. Explain how carbon isotope measurements can
help
determine the relative importance of some of these sources.
6.
Summarize the chemistry and environmental consequences of sulfur in
the atmosphere.
7.
Outline the major steps in the production of photochemical smog,
including the roles of H2O, CO, and hydrocarbons.
*************************************************************************
********
12 Radioactivity in the environment
1.
Characterize the various radioactive decay processes in terms of
the nature of the emitted radiation, its penetrability and interaction
with
matter.
2.
Define: natural decay series, secular equilibrium. Explain how
naturally-formed short-lived nuclides can persist in the environment.
3.
Discuss the principal characteristics of cosmic radiation.
4.
Explain the meaning and use of the measurement terms, rem and rad.
5.
Summarize the major sources of environmental radioactivity, both
natural and anthropogenic, with particular reference to human exposure.