CHEM 151: General Chemistry I
About 3 hours 15 min on Lorea11 chapters1 school
Looking up CHEM 151 (General Chemistry I)? This is the 16-week general chemistry course STEM, pre-med, and allied-health majors take when the first quantitative chem class shows up on the schedule.
At University of Arizona, CHEM 151 is the code on the schedule, the textbook list, and the exam. This page follows Chemistry 2e (OpenStax) chapter for chapter - 11 chapters over 16 weeks - and opens a free Lorea course with no signup.
If you are asking "is CHEM 151 hard?" start with the failure points below, then drill the 11 OpenStax chapters instead of rereading the PDF.
Lorea is independent and not affiliated with University of Arizona.
What CHEM 151 covers
CHEM 151 covers Essential ideas and measurement, atoms/molecules/ions, composition and solutions, stoichiometry, thermochemistry, electronic structure and periodic trends, chemical bonding and molecular geometry, advanced bonding theories, gases, liquids and solids, solutions and colloids. The sequence matches Chemistry 2e (OpenStax), the open textbook this page is built from - 11 chapters across a 16-week semester, in the same order your lecture is likely to follow.
What makes CHEM 151 hard
Stoichiometry and limiting reagent (Ch 4) is the single biggest failure point; then VSEPR molecular geometry (Ch 7); unit conversion and significant figures trip students in week 1; gas law problem setup (Ch 9). Those are the spots students miss on timed CHEM 151 exams even after they "read the chapter." Drill them with retrieval - practice questions, blank figures, setup-only problem sets - not another highlight pass.
CHEM 151 chapter-by-chapter
- 1.Essential Ideas
- 2.Atoms, Molecules, and Ions
- 3.Composition of Substances and Solutions
- 4.Stoichiometry of Chemical Reactions
- 5.Thermochemistry
- 6.Electronic Structure and Periodic Properties of Elements
- 7.Chemical Bonding and Molecular Geometry
- 8.Advanced Theories of Covalent Bonding
- 9.Gases
- 10.Liquids and Solids
- 11.Solutions and Colloids
How to study for CHEM 151
1. Do the math before you reread
Start every week with the failure points in CHEM 151: Stoichiometry and limiting reagent (Ch 4) is the single biggest failure point; then VSEPR molecular geometry (Ch 7); unit conversion and significant figures trip students in week 1; gas law problem setup (Ch 9). Write the setup, not just the answer.
2. Keep a unit-and-formula card
Most CHEM 151 misses are unit errors or a missing conversion. One card for SI prefixes, gas-constant units, and ΔH signs beats a highlighted PDF.
3. Redraw structures from memory
Lewis structures, VSEPR shapes, and orbital diagrams have to come out of your hand, not the figure caption. Close the book and redraw.
4. Mix old chapters into new problem sets
Stoichiometry does not retire when you reach gases. Interleave two older chapters with the current one so the sequence stays loaded.
5. Sit a free practice pass
Use the free Lorea course for General Chemistry I - no signup - and miss on purpose once so you know which of the 11 chapters still wobble.
Schools that use CHEM 151
CHEM 151 is the published course code at each of these schools:
- University of Arizona
FAQ
Is CHEM 151 hard?
Yes - CHEM 151 is a weeder for many students because of specific failure points, not because the textbook is obscure. Stoichiometry and limiting reagent (Ch 4) is the single biggest failure point; then VSEPR molecular geometry (Ch 7); unit conversion and significant figures trip students in week 1; gas law problem setup (Ch 9). Plan weekly retrieval around those, not a single reread of Chemistry 2e (OpenStax).
How many chapters is CHEM 151?
CHEM 151 is 11 chapters in this guide, aligned to Chemistry 2e (OpenStax): Ch 1 Essential Ideas; Ch 2 Atoms, Molecules, and Ions; Ch 3 Composition of Substances and Solutions; Ch 4 Stoichiometry of Chemical Reactions; Ch 5 Thermochemistry; Ch 6 Electronic Structure and Periodic Properties of Elements; Ch 7 Chemical Bonding and Molecular Geometry; Ch 8 Advanced Theories of Covalent Bonding; Ch 9 Gases; Ch 10 Liquids and Solids; Ch 11 Solutions and Colloids.
What textbook does CHEM 151 use?
CHEM 151 in this guide follows Chemistry 2e (OpenStax). Your section may assign a different commercial book; the chapter titles above are the OpenStax sequence used at the listed schools.
What is the difference between CHEM 151 and the next course in the sequence?
CHEM 151 is the first course in the sequence. The follow-on course (often numbered one digit higher, or labelled II) covers the remaining chemistry units. Check your school's catalogue for the exact next code - it is not the same at every campus that uses CHEM 151.
Which schools use the CHEM 151 code?
CHEM 151 is used at University of Arizona. If your campus prints this exact code, the chapter list on this page is the one to study against.
Are there free CHEM 151 flashcards?
Yes. The free Lorea General Chemistry I course linked on this page covers all 11 Chemistry 2e (OpenStax) chapters as retrieval practice — use it like CHEM 151 flashcards without signing up.
What is on CHEM 151 exam 1?
Exam 1 in CHEM 151 usually covers the first third of the term — often Essential Ideas, Atoms, Molecules, and Ions, Composition of Substances and Solutions, and more depending on your syllabus. Match the chapter list above to your exam date; the free Lorea course lets you run retrieval on those units before the midterm.