students and professor looking at petri dish

General Chemistry FAQs

Selecting a General Chemistry sequence

What is the difference between the Chem 105/106 and Chem 111A/112A sequences?

Chem 111A covers introductory quantum mechanics and a rigorous treatment of atomic wavefunctions. In Chem 105, this content is replaced by a review of fundamentals, including solution chemistry, stoichiometry, calculations involving chemical reactions, and gas properties. Chem 106 covers most of the same material as Chem 112A, but advanced applications are removed to allow more time for in-class active learning.

Which General Chemistry sequence should I choose?

All first-year students intending to register for either Introductory General Chemistry I (Chemistry 105) or General Chemistry I (Chem 111A) in the fall are expected to take the online chemistry diagnostic exam before you register your courses for Fall 2021.

Based on your performance on the diagnostic exam, your SAT/ACT math score, your AP Chemistry and/or AP Biology scores, and/or your intended major, your four-year advisor will provide a corresponding (non-binding) recommendation for the course selection in the fall semester (Chem 105 or Chem 111A). You will receive advice for your course selection for the spring semester (Chem 106 or Chem 112A) from your chemistry instructors and your four-year advisor based on your performance in the fall semester. Students should consider the course descriptions and prerequisites for both fall and spring semesters to choose the appropriate General Chemistry sequence. However, all students may change between course sequences, in either direction, at semester breaks.

All students should review the pre-requisite knowledge and skills for General Chemistry I and II (Chem 111A/112A) during the registration process, if they are considering taking an introductory course in chemistry. 

When reviewing, students should note key differences when something is designated with “proficiency” vs. “familiarity.”

Proficiency is used when a concept or skill will not be taught directly in class, but will be tested. For example, understanding simple trigonometric relationships such as sin⁡θ=0 when θ=0,π,2π,… is tested in Chem 111A, but not taught directly. 

Familiarity is used when having been exposed to a concept would be generally beneficial, but those concepts will be taught directly in lecture before being tested. 

Review of the General Chemistry II (Chem 112A) prerequisite topics is especially important regarding fall registration. If a student self-assesses as not proficient in the skills/knowledge listed, those topics will be taught directly in Introductory General Chemistry I (Chem 105) and we recommend enrollment in this sequence (Chem 105/106).

Students should also note that the majority of topics listed as prerequisite knowledge for General Chemistry II (Chem 112A) will be reviewed in the General Chemistry Laboratory course (Chem 151/152). Thus, students will have the opportunity to re-acquaint themselves with these ideas prior to the start of Chem 112A. 

The pre-requisites may be found here:

Please contact Dr. Megan Daschbach ( or Dr. Jia Luo ( for further advice.

General Chemistry diagnostic exam

All first-year students registering for Introductory General Chemistry I (Chemistry 105) or General Chemistry I (Chemistry 111A) in the fall are expected to take the online chemistry diagnostic exam.

Who should take the online general chemistry diagnostic exam?

If you are planning to take Introduction to General Chemistry I (Chem 105) or General Chemistry I (Chem 111A) and you are a first-year student, you should take the online general chemistry diagnostic exam.

What is the deadline for taking the online diagnostic exam?

Before you register General Chemistry courses for Fall 2021

Where can I find tutorials and practice problems before taking the diagnostic exam?

Tutorials and problem sets are available for you to practice before you take the online diagnostic exam.

Please note, on this website of tutorials, there are links to login to online quizzes and an online diagnostic exam. These links are no longer current and will not lead you to the correct login page for the online diagnostic exam. The only way to access the diagnostic exam is to go through the diagnostic exam login.

If I do not pass the online exam, may I still enroll in Chemistry 105 or 111A?

First, we would like to clarify that your results will not be graded pass/fail. We recognize that, as a diverse group from around the globe, WU students arrive with a range of backgrounds and previous experiences. However, regardless of your previous preparation, by being admitted to WU, you have demonstrated considerable academic prowess and promise. The purpose of this online diagnostic exam is to help the instructors in Chemistry 105 and 111A, as well as your four-year academic advisor, advise you on how to make an easier transition into the rigorous academic program we offer. Regardless of your exam results, you will be allowed to enroll in either Chemistry 105 or Chemistry 111A.

If I do not do well on the online diagnostic exam, will I do poorly in Chemistry 105 or 111A?

No. Based on your online diagnostic exam results, we will suggest activities that will help you achieve at your highest level in either course. The first suggestion may be to review the online tutorials and take the online exam a second time. Further suggestions may include enrollment in peer-led team learning (PLTL) groups, which meet weekly during the course of the semester, or enrollment in a supplementary problem-solving workshop held by Cornerstone: Center for Advanced Learning. You may enroll in either of these options once you come to Washington University in the fall. PLTL groups are increasingly popular with WU general chemistry students and have been shown to help students better understand concepts covered in the course. Therefore, you are recommended to look into joining a PLTL group upon your arrival at WU, regardless of your exam results. Your performance on the online diagnostic exam will have no effect upon your grade in Chemistry 105 or 111A and will only be used by the course instructors and your four-year academic advisor to better advise you.

When will I find out the results of my online exam?

After the diagnostic exam deadline, your exam results will be forwarded to your four-year academic advisor. Your four-year academic advisor will discuss your exam results with you at your first meeting together. At that time, you will be informed about which General Chemistry sequence (Chemistry 105/106 or Chemistry 111A/112A) and supplementary aids we recommend for you.

How is General Chemistry at WU different from high school AP chemistry?

Fundamental concepts form the foundation for both university chemistry and high school AP chemistry. However, at a university, the concepts are explored in greater depth. The difficulty of the problems you will be asked to solve and the number of logical or mathematical steps required for the final solution are also more complex. In most high-school chemistry courses, solutions to problems are straightforward, requiring the application of an equation, formula, or definition in order to reach a correct solution. On the other hand, problems given in university courses are more typical of those seen in the real life of a practicing scientist, physician, or engineer, where problems often require a number of calculation steps, the ability to separate necessary from extraneous data, and the proper linkage of multiple concepts. In practice, scientific problems are not always clear cut. They require practitioners to have command of a broad range of concepts, to get to the essence of the problem (sometimes separating out extraneous data), and to make and execute a successful plan of attack. The emphasis at the university level is on the development of these real-world skills.

If I scored a 5 on the AP Chemistry test, do I need to take the online diagnostic exam?

Yes. If you are an incoming first-year student and decide to take Chemistry 105 or 111A in the fall semester, you will be expected to take the online exam. Taking the online diagnostic exam qualifies you to participate in the very popular peer-led team learning (PLTL) study groups and gives you access to other supporting programs developed for Chemistry 105 and 111A.

How can I request accommodations for the diagnostic exam?

Students who need accommodations should first get approval from disability resources, then contact Dr. Jia Luo ( with the approval. Requests will be assessed case-by-case to determine if we can offer accommodations.

Whom should I contact if I have problems or questions?

You may contact Dr. Jia Luo via e-mail at if you need further assistance.

Chemistry courses after General Chemistry

How does each General Chemistry sequence affect registration for later chemistry courses?

Chemistry majors who begin in the Chem 105/106 sequence will be required to complete an online course module covering introductory quantum mechanics prior to enrolling in Physical Chemistry I (Chem 401), which is normally taken in the junior year.  Students in either course sequence will be prepared to take Organic Chemistry I (Chem 261) and Organic Chemistry II (Chem 262).  The introductory quantum mechanics course module will also be made available to students who are not chemistry majors.

Will I take a different General Chemistry lab based on which sequence I'm in?

No. Students in both sequences will take the same General Chemistry Laboratory courses, Chem 151 and Chem 152.

Course descriptions and prerequisites

Where can I find more information about each General Chemistry sequence?

Read through the webpages on each sequence: Chemistry 105/106 and Chemistry 111A/112A.

What is the course description with prerequisites for Chem 105?

This course traces the development of chemistry from early atomic theory to modern descriptions of structure, bonding, and intermolecular interactions. Over the course of the semester, the students learn how macroscopic observations of stoichiometry, chemical reactions, the properties of elements and compounds, and chemical periodicity developed into the microscopic understanding of molecular structure and bonding. The semester begins with fundamentals related to stoichiometry, chemical reactions, solution chemistry, and gas properties, with an emphasis on quantitative problem solving. The octet rule, Lewis structures, and valence-shell-electron-pair repulsion (VSEPR) theory are then introduced as early efforts to describe the stability and structures of molecules. The localized electron model (LEM) and molecular-orbital theory (MOT) are next described as modern descriptions of chemical bonding. The course concludes with intermolecular forces such as hydrogen bonding and van der Waals interactions.

Prerequisite skills include the following: proficiency in algebra, familiarity with solving simple quantitative word problems, and familiarity with unit analysis.

What is the course description with prerequisites for Chem 106?

This course covers chemical equilibrium, thermodynamics, and kinetics at a fundamental level, with an emphasis on in-class problem solving. Gas-phase reactions, heterogeneous (multi-phase) reactions, acid-base reactions, and solubility equilibria are introduced first. Chemical thermodynamics is then taught in its relation to chemical equilibrium. The course finishes with chemical kinetics and rate laws. The content is similar to that in Chem 112A, but advanced applications are omitted to allow more in-class guided active learning.

Prerequisite skills include the following: proficiency with algebraic manipulation of equations and relationships, familiarity with solving multistep quantitative word problems, familiarity with unit analysis.

Knowledge-based prerequisites include the following: familiarity with (1) stoichiometry, balancing chemical equations, determining the limiting reagent; (2) compounds and 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; (8) balancing redox reactions; and (9) the ideal gas law and Dalton's law of partial pressures. All these prerequisites are provided by Chem 105.

What is the course description with prerequisites for Chem 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

What is the course description with prerequisites for Chem 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