Prep Chem as a Prerequisite to Gen Chem

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Prep Chem as aPrerequisite to Gen Chem

• Crystal L. Yau, Ph.D.
• Associate Professor
• Chemistry Coordinator
• at the Community College of Baltimore County,
  Catonsville

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My background

• I began teaching at a community college in
  California back in 1973.
• After 7 years of full-time teaching, I took a few
  years off to raise a family.
• As my children got older we moved to Baltimore
  and I started teaching at Essex Community College
  and at Towson University as an adjunct.
• In 2000, I became a full-time lecturer and
  General Chemistry Coordinator at Towson
  University.
• In 2004, I joined the faculty at Community
  College of Baltimore County (CCBC).

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• Courses offered at CCBC
• Chemistry for Nonscience Majors
• 3 credits but meet 4 hours/week
• Prep Chem
• Introduction to Organic Biochemistry
• Gen Chem I and II
• Organic Chem I and II

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The Prerequisite to Gen Chem at CCBC Student
wishing to enroll in Gen Chem must either pass
the Chemistry Placement Test or obtain a grade
of C or better in our Prep Chem (lecture and
lab), regardless of whether the student has taken
high school chemistry.
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• Why is there a necessity of such a prerequisite?
• Large numbers of students in Gen Chem were having
  difficulty in passing the course.
• Some took high school chemistry many years ago.

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• Those who took it recently, admit they do not
  remember anything.
• Some claimed they had poor chemistry teachers in
  high school.
• Whatever the reason may be, the effect was

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that we had to teach gen chem from scratch,
and there simply was not enough time to cover
all that we wanted to cover in Gen Chem. We often
had to rush through important topics at the end
of the semester, and students complain we cover
too much material.
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• What I try to do in Prep Chem
• Instill good study habit Collect homework
  and/or give quiz every period so they have to
  keep up.
• Use electronic HW only sparingly as I want them
  to learn to setup their problems.
• Teach them problem solving techniques
  dimensional analysis how to handle percent
  problems.
• Drill them on the basics repeatedly.

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• In the Prep Chem lab (1 credit, 3 hrs)
• We use an in-house lab manual designed to give
  them a chance to
• learn basic lab techniques such as weighing by
  difference, measurement of volume using
  Archimedes Principle, use of pipet and buret.
• give them the opportunity to transfer samples
  (liquids, solids) from one container to another.

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• practise graphing by hand, finding slope and
  y-intercept.
• practise with percent calculations.
• become familiar with reading various number
  scales (watching for sig. fig. and units) 10-mL
  and 50-mL graduated cylinders, axes on the graph.
  This is NOT easy for them!

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• All experiments have post lab questions that
  require critical thinking and expression in full
  sentences and well-organized paragraphs.
• Post lab questions begin to prepare them to write
  formal lab reports by asking them questions about
  effect of error on their final results.

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• Generally great accuracy and precision are not
  required at this level.
• The experiments are usually ones that relate to
  their everyday livessuch as water in popcorn,
  fat in potato chips, composition of pennies,
  dyes used in candies.

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How the prerequisite is implemented Students
registering online are blocked by the computer
from registering for Gen Chem if their records do
not show they have taken Prep Chem. They are
instructed to see an academic advisor, who tells
them about the prerequisite.
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The academic advisors look over their transcript
and sometimes waive the requirement, or they send
them to the Chemistry Department to take the
Chemistry Placement Test. Usually students arrive
and tell us they "just need our signature" but
we proceed to explain the need for the placement
test and give them an information sheet.
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• Information given to students about the placement
  test
• They can take the test only once, and only at one
  campus.
• (We keep a good record and immediately notify
  the other campuses by email when a student has
  taken the test.)

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• To prepare for the test, they can check out a
  prep chem text we have on reserve at our
  libraries.
• They are to study the first 8 chapters and then
  come back to arrange for a time to take the test.
• Most of the time, they do not come back and just
  enroll in the Prep Chem course.

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On their information sheet, we also provide 5
sample questions with answers
1. The species in an aqueous NaCl solution
are A. NaCl and H2O B. Cl2, Na, and
H2O C. Cl-, Na2, and H2O D. Cl2, Na2, and
H2O E. Na, Cl-, and H2O
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2. How many atoms of K are in 7.82 x 10?5 mole of
K? (Avogadros number is 6.02 x 1023, and the
atomic mass of K is 39.10 g/mole.) A. 4.71 x
1019 B. 7.70 x 1027 C. 4.71 x
1028 D. 2.00 x 10?6 E. 3.06 x 10?3
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3. A chemist places an empty beaker onto a
balance pan and records 127.834 g in his
notebook. If the water that he adds to the
beaker weighs 53.785 g, what would his next entry
be in his notebook? Mass of empty beaker
127.834 g Mass of beaker water
? A. 53.785 g B. 74.049 g C. 127.834
g D. 181.619 g E. none of the above
The test has a few lab related questions.
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• How do students do on this test?
• Passing grade is 80.
• For those with 76, we examine their transcripts
  and in some cases we waive the prerequisite.
• Roughly 20-25 of the students pass the test.
• About 20 who failed the test have not returned
  to register...but..

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• this can be due to different reasons
• They may have difficulty fitting a course in
  their schedule and do intend to enroll some time
  in the future.
• They have decided to enroll somewhere else.
• During the summer, we get a significant number of
  students from other colleges. These usually do
  not want to take Prep Chem.

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However, this does not mean we are doing the
wrong thing. Many of the students who take our
Prep Chem do not go on to take our Gen Chem
because they are transferring to other
institutions, but they are planning to take Gen
Chem elsewhere. They tell us they feel they are
getting a good foundation by taking our Prep Chem.
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• How good is the placement test as a criterion?
• Prerequisite has been in effect only since Fall
  2007.
• We don't have enough data to give you statistics,
  but can only give you anecdotal information.
• I was hesitant in giving this presentation, but
  was urged to do so.

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• Those who passed the test with 80 had no trouble
  passing our Gen Chem.
• Those with 76 and got the prerequisite waived
  had mixed results. It depended very much on
  their motivation and study habits.
• What is most disturbing is that not all of those
  in prep chem at the end of the semester can pass
  the placement test!

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• The placement test is NOT difficult. It is much
  easier than the Final Exam in Prep Chem.
• It appears that students just cannot retain the
  information they learned!
• There are other reasons that I will bring up
  later.

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• Did the prerequisite achieve what we had
  intended?
• It is too early to tell.
• There are still a lot of problems that we have to
  iron out.
• When we started offering Prep Chem at
  Catonsville, I taught it exclusively and do not
  have first hand information on what is happening
  in Gen Chem since the prerequisite was in place.

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• Gen Chem has been taught by a new instructor who
  had never taught it without the prerequisite and
  therefore could not tell whether there is a
  difference.
• Next semester I will start teaching Gen Chem and
  will be able to see for myself. However I can
  relate what the new faculty has noticed.

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Partnerships in Chemical Education? In order of
Prep Chem to work properly as the prerequisite
for Gen Chem, it requires a great deal of
"partnership" coordination and cooperation with
various groups.
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• Working closely with the academic advisors
• We have found a significant number of students in
  Gen Chem without the prerequisite and struggling
  to pass the course.
• This has defeated the whole purpose of having
  Prep Chem as a prerequisite!
• Apparently these students got waived by
  misinformed part-time academic advisors.

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• There is also an advisor in the athletic
  department who signs students in whatever
  chemistry course fits in their athletic schedule!
• Those who received good training in Prep Chem
  find it incredibly boring while these
  under-prepared students are struggling.

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Suggested Solution Request to attend one of the
advisors' weekly meetings and clarify how the
prerequisite work. Specify that if it is unclear
whether a student has fulfilled the prerequisites
at another college, simply have the student take
the placement test.
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• 2. Working closely with the chem faculty
• It is of utmost importance to come to an
  agreement on exactly which topics should be
  covered in Prep Chem so that it is not overly
  redundant when students arrive at Gen Chem.
• 3. Working closely with the adjunct faculty
• Make sure adjuncts understand how the
  prerequisite works.

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Recommended Solution Develop a common Final Exam
to help ensure all sections of Prep Chem cover
the same material.
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Faculty must agree on how to handle students in
Gen Chem who enrolled without the prerequisites
(whatever the reason may be Currently some Gen
Chem instructors are skipping the first 4
chapters and assume students already know the
material. Some Gen Chem instructors go over the
first 4 chapters as review. Some teach the
chapters as they used to before the prerequisite
is in place.
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• 4. Working closely with program directors of
  programs that require students to take the Prep
  Chem course.

Our Pre Chem course is serving too many other
purposes It serves also as the 1st semester of
"allied health chem" (also known as GOB) to be
followed with the intro to Organic and Biochem.
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• It is required of students going for the dental
  hygiene at CCBC.
• It is required of students going for the
  accelerated nursing program at UM.
• A large number of students are taking it for
  admission to the Respiratory Therapy program at
  Essex.
• It is a Gen Ed course and must fulfill the
  requirements of being a Gen Ed course.

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• Problem We felt we needed to cover a wide range
  of topics to satisfy all the different majors.
• e.g. We felt we needed to cover gases in more
  detail for the sake of the Respiratory Therapy
  students.
• We also felt we needed to cover
  intermolecular forces for the sake of those who
  continue on to the Intro to Organic and Biochem.

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• If we teach too many topics in prep chem, it
  would overwhelm the students.
• Solution If it were possible, teach a
  separate course specifically for prepping for Gen
  Chem.
• Work out a detailed scheme on what is to be
  covered in the Prep Chem and what is to be
  covered in the Gen Chem.

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For example, In Prep Chem we require students to
learn the names and formulas of only 8 polyatomic
ions, leaving the rest to Gen Chem acetate,
nitrate, hydroxide, chlorate, carbonate, sulfate,
phosphate and ammonium ion.
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In molecular geometry, we teach expanded octet
only in Gen Chem. In electron configuration, we
barely mention quantum numbers in Prep Chem,
leaving the details to be taught in Gen Chem. In
Prep Chem we only cover the gas properties and
the Kinetic Molecular Theory of gases, and do not
do any calculations involving the gas law.
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Gen Chem instructors need to know which topics
they can cover quickly as review and which
topics they should spend time to go over
slowly. These topics include solution
stoichiometry, thermochemistry, Lewis structure
of more complex molecules, resonance structures,
valence bond theory, molecular orbital theory.
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Problem Selecting questions for the chem
placement test was not easy. Suggestions
Students who cannot pass Gen Chem are usually
those who have very weak math background. I
would concentrate more on mathematical problems
rather than chemical.
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• Summary of what to look out for in implementation
  of Prep Chem as Prerequisite for Gen Chem
• Make sure academic advisors understand what the
  prerequisites are. When in doubt have the
  student take the chem placement test. Attend one
  of their weekly meetings.
• Make sure all of the chem faculty, full-time and
  adjuncts, know exactly what is to be taught in
  Prep Chem and in Gen Chem.

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• Avoid using the same course to satisfy the
  requirement of a wide variety of programs.
• Work out a detailed scheme as to what should be
  covered in Prep Chem, and what should be covered
  in Gen Chem.

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If you need further information, you may contact
me cyau_at_ccbcmd.edu Office 443-840-5932