Chemistry 111A/112A

Diagnostic Exam

Taking General Chemistry I (Chem 111A) in the fall? You need to take the online diagnostic exam!

All first-year students registering for General Chemistry I (Chem 111A) in the fall are expected to take the online chemistry diagnostic exam between June 10, 2019, and July 5, 2019.

The objectives of the online diagnostic exam include the following:

  • Assess if Chem 111A/112A is the optimal course sequence for you, so you can obtain helpful placement advice from us.
     
  • Identify students who may benefit from supplementary resources at WU, such as extended recitation sections and peer-led team learning (PLTL) study groups. Recommendations regarding extended recitations will be given to you by late August.

You will need your six-digit WU student ID number to access the diagnostic exam, but no password is required. If you have questions about your student ID number or any problems logging onto the website please, please contact Dr. Jia Luo via e-mail (JLUOA@WUSTL.EDU) or phone (314-935-4163). Contact by email is preferred.

Note that each student has only one attempt to complete the diagnostic exam. We recommend you first read the instructions for taking the diagnostic exam before attempting the exam.

 

DIAGNOSTIC EXAM LOGIN

Required Materials

Textbook

Principles of Modern Chemistry (8th edition) by D. Oxtoby, H. Gillis, and L. Butler. Both the electronic version and the hardback version of the text are acceptable.

Calculator

Only the following models of electronic calculator will be allowed during quizzes and exams: TI-30 XS Multiview (preferred 4-line model), TI-34 Multiview (preferred 4-line model), TI-30Xa (acceptable 2-line model), TI-30X IIs (solar 2-line model). Allowable calculators must be four-line or two-line, non-programmable, non-graphing calculators. This policy will be strictly enforced with no exceptions. Acceptable calculators are available from the WU bookstore as well as Amazon, Walgreens, Staples, Office Depot, and other office supply stores.

Online Homework

All students must have access to the OWL (version 2) online homework platform that is interfaced with Canvas. Access codes are available for purchase through the campus bookstore. NOTE: Problems from earlier versions of the textbook will often be numbered differently.

Recitation Subsections

Every student who registers for Chemistry 111A must register for a lecture section that meets MWF, as well as a recitation subsection that meets on Thursdays. You will find information below to help you choose which style of recitation might be best for you. Even though all recitations cover essentially the same material and example problems, there will be two different formats offered. You should choose the recitation format that you feel best suits your approach to learning and perceived level of preparedness for Chemistry 111A.
 

Recitation Types

Classic (regular) format: These recitation sections are 1 hour in length. The format includes a quiz during the first 15 minutes of class. Following the quiz, a brief summary of the week’s main lecture topics is presented and challenging practice problems are worked for the remainder of the class period. A trained graduate Assistant in Instruction (AI) leads this problem-solving session.

POGIL (guided-inquiry) recitations: These recitation sections are 1.5 hours (30 minutes longer than the regular recitation sections). This format also includes a quiz during the first 15 minutes of class.  Following this quiz, and a brief summary of the week’s topic by the graduate AI, students will work in small, structured groups on guided-inquiry problem sheets that have been written specifically for Washington University Chemistry 111A topics.  These problem sheets are designed to help develop self-teaching and problem-solving skills, as well as to call attention to crucial concepts discussed in lecture through exploration and analysis of challenging example problems.

The custom-designed exercises and selection of problems include an emphasis on conceptual aspects of the topic. This format is designed to help you gain a deeper understanding of the concepts underlying problems.
 

Comparison of Regular and POGIL Recitations

Although both regular and POGIL recitations cover the same topics with the same practice problems in every weekly session, POGIL worksheets break down each problem into several guiding questions to lead students to think through the concepts and solve the problem in a stepwise manner.

Example Problem for a Specific Topic: The Bohr Equation

Problem: What is the wavelength (in nm) of the photon absorbed by a Li2+ ion when the ion is excited from the 2nd excited state to the 4th excited state?

In a regular recitation, after a brief review of the topic “The Bohr Equation,” this problem would be presented as written. Students would then be asked to work the problem either individually or with other peers. The AI would circulate around the room to answer any questions while students first attempt the problem. Finally, the AI reviews the problem on the board and shares the correct answer to ensure understanding.

In a POGIL recitation, the worksheet addresses the same problem in a stepwise manner as shown below:

  1. What is the value of Z for the Li2+ ion?     
  2. What feature of the Li2+ ion allows it to be analyzed using the Bohr model? Could Li+ be used instead?
  3. What are the values of n for the initial and final states described above?                                                
  4. Was a photon absorbed or emitted in this process? Explain your answer.
  5. Calculate the energy of the transition in part c.
  6. Describe how the transition energy of the Li2+ ion is related to the energy of the photon involved in the process.
  7. Calculate the wavelength of the photon absorbed by this ion.

As you can see, in both recitation sections students ultimately determine the wavelength of the photon absorbed in this transition.

However, when answering the POGIL guiding questions, students are prompted to address key concepts involved in the problem and guided through the problem-solving process. The group work format provides a structured environment for students to discuss with their peers. By articulating their opinions and communicating with peers using scientific language, the students’ understanding of certain concepts becomes polished. In general, students’ confidence and communication skills are strengthened through practice and discussion of the problems.


Choosing the Best Recitation Style for You

Research studies show that the POGIL-style recitation is beneficial for most first year students, especially in the early times of developing self-teaching, self-learning, and problem-solving skills. To decide whether a regular or POGIL recitation will benefit YOU the most, consider the following questions:

  • Do you think you would benefit more from spending 30 minutes longer in recitation every week?
  • Do you think you would benefit more from a guided approach to the problem-solving process?
  • Do you think exchanging ideas with your peers in a structured environment would help solidify your understanding of a topic?

If you answered yes to all of these questions, then the POGIL-style recitation is recommended for you.

If your answer to one or more of these questions is no, you may want to consider enrollment in a regular recitation. No matter what style you choose, everyone has access to the same information. All students are encouraged to check out the POGIL worksheets, which are available through the course webpage at the end of each week.

Course Descriptions

The General Chemistry sequence (111A/112A) is recommended for students who have taken AP Chemistry or two years of chemistry in high school OR students who have taken one year of chemistry and one year of physics in high school.

General Chemistry I (111A)

In the early 1900s, the periodic table of the elements hung in laboratories and classrooms around the world, nearly as it appears today, and no one could explain why it was arranged as it was. That explanation required the discovery of the mysterious, dual wave-particle behavior of the electron, which forms the basis for most of modern chemistry. This course traces the story of the electron and the strange behavior resulting from its dual wave-particle character – from free electrons, to electrons in atoms, to electrons in molecules. The electron and its properties will be shown to be responsible for atomic structure, atomic orbitals, atomic spectroscopy, chemical periodicity, the arrangement of the periodic table, chemical bonding, molecular geometry, and intermolecular forces. Students will achieve a strong foundation in molecular structure, chemical bonding, and introductory quantum mechanics.

Prerequisite skills:

  • Proficiency in algebra and trigonometry
  • Proficiency with simple quantitative word problem solving
  • Proficiency with unit analysis

Knowledge-based prerequisites:

  • Familiarity with kinetic energy, potential energy, forces (F = ma), velocity, and a conceptual idea of momentum
  • Understanding of vectors and how to graph them

General Chemistry II (112A)

This course covers chemical equilibrium, thermodynamics, and kinetics, and their roles in describing and determining chemical processes. The key concepts of chemical equilibrium for gas-phase reactions, heterogeneous (multi-phase) reactions, acid-base reactions, and solubility equilibria are introduced first. The next section of the course describes chemical thermodynamics with a focus on heat, work, internal energy, enthalpy, entropy, and Gibbs free energy. Key connections are made between equilibrium and thermodynamics, and students learn how to predict the spontaneous direction of a reaction from thermodynamic data. Electrochemistry--the study of the interconversion of chemical and electrochemical energy--is presented as a practical application of thermodynamics. Chemical kinetics is then introduced with a focus on the factors that influence the rate of a chemical reaction. Phase diagrams, fractional distillation, and colligative properties are the final topics covered. The content is similar to that in Chem 106, but with a strong emphasis on advanced applications.

Prerequisite skills:

  • Proficiency in algebraic manipulation of equations and relationships
  • Proficiency with simple quantitative, multi-step word problem solving
  • Proficiency with unit analysis
  • Understanding of how to interpret graphical data and information
  • Familiarity with integrals and derivatives

Knowledge-based prerequisites:

  • Proficiency with (1) stoichiometry, balancing chemical equations, determining the limiting reagent;  (2) compounds, chemical formulas; (3) unit conversions, including grams to moles; (4) determining molarity and dilution calculations; (5) states of matter; (6) fundamental acid/base reactions in water; (7) writing net ionic equations; and (8) balancing redox reactions
  • Familiarity with (1) mechanical energy and work (force × distance); (2) thermal energy and heat; and (3) the ideal gas law and Dalton’s law of partial pressures