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Practice sets
25 original problems per chapter in three levels: Easy, Exam and Challenge. Full numbered solutions, structures drawn for you.
● Beta · free access while we build
Orgo that finally clicks.
Original practice problems with full step-by-step solutions, one-page mechanism cards and 3D reaction stories, made for Organic Chemistry 1 & 2 and pre-med / MCAT prep.
Every solution fully worked
Every answer independently checked
Printable PDFs
numbered steps + the "common mistake" for every problem
no sign-up needed
Try one. This is what every problem looks like.
EasyCh 7 · Williamson ether synthesis
You want to make ethyl isopropyl ether (2-ethoxypropane). Which route is better?
Answer Route 1. The reaction is SN2; Route 2 mainly gives propene by E2.
- The Williamson synthesis is an SN2 attack by an alkoxide on an alkyl halide, so the halide should be methyl or primary.
- Route 1 attacks a primary carbon (bromoethane): good for SN2.
- Route 2 attacks a secondary carbon with a strong base; E2 competes and wins, so propene is the main product.
- Make the alkoxide by deprotonating the alcohol with NaH (or Na metal).
- Common mistake: picking the pair by which fragment looks "bigger". Put the more substituted carbon on the oxygen (alkoxide) and the less substituted carbon on the halide.
Pick a route, then reveal the full solution. Every problem in the packs has this format.
the toolkit
What's inside
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Mechanism cards
One page per mechanism: arrows, the rate law, stereochemistry, and the exam trap. Print it, stick it on the wall.
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The Scary Molecule Set
Drug-sized molecules that look terrifying but only need skills you already have: hybridization, degrees of unsaturation, separations.
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3D reaction stories
Rotate SN2 inversion, SN1 racemization and E2 anti-periplanar geometry in your browser, then step through each reaction. Try one.
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Video walkthroughs
Short pen-on-page solutions of the trickiest problems. First five come with the SN/E chapter.
real pages, not mock-ups
A look at the PDFs
free to play with
The 3D Lab
Orgo is a 3D subject taught on a flat page. These interactive stories let you rotate the molecules and step through each reaction. Drag to rotate, scroll or pinch to zoom, use the step buttons to go slowly.
5 free stories (Chapter 7)
- SN2: Walden inversion, the umbrella flips
- SN1: carbocation and racemization
- SNi: ROH + SOCl₂ gives retention
- E2: anti-periplanar elimination
- E2 in cyclohexane: trans-diaxial H/Cl
More are being built, chapter by chapter (next: alkene additions, with the Chapter 8 set). Needs an internet connection and a recent browser; works on phones.
How to use it
Try it cold
Attempt the problem before you look. Mark what you could not do.
Read the steps
Compare your path with the numbered solution. The "common mistake" line is usually where marks are lost.
Re-test later
Redo the ones you missed two days later, then a week later. That is where retention is built.
honest status
Chapters
Aligned to a standard two-semester organic sequence. We only list what exists; the rest is marked.
| Topic | Practice set | Status |
|---|---|---|
| Ch 1 · Structure, bonding, hybridization | 25 problems · free | Ready |
| Ch 2 · Representations, resonance, curved arrows | 25 problems · Core | Ready |
| Ch 3 · Acids & bases | 25 problems · Core | Ready |
| Ch 7 · SN2, SN1, E2, E1 + mechanism cards + 3D stories | 25 problems + 8 cards + 5 3D stories · free | Ready |
| Scary Molecule Set | 25 problems · 8 free preview | Ready |
| Ch 8 · Alkene additions | — | Next |
| Ch 6 · Kinetics, energy diagrams, arrow-pushing | — | Next |
| Ch 4, 5 · Alkanes, cyclohexane, stereochemistry | — | Next |
| Ch 9, 10, 11 · Alkynes, radicals, synthesis | — | Later |
| Orgo 2 · Aromatics, carbonyls, spectroscopy and more | — | Later |
free while we're in Beta
Get access
The free sample is yours now, no strings. Beta list members also get the Core pack free when it opens. The listed prices are planned for after Beta and may change.
Free Sample
$0
- Chapter 1 practice set (25 problems)
- Chapter 7 practice set (25 problems)
- Chapter 7 mechanism cards
- 5 interactive 3D stories for Chapter 7
- Scary Molecule Set preview (8 problems with solutions)
Orgo 1 Core
Opening soon
Beta list members get it free at launch. Planned price after Beta: $19.
- Chapters 2 and 3 practice sets
- The full Scary Molecule Set (25 problems)
- Everything in the Free Sample
- More chapters and 3D stories as they land
Full Orgo 1
Coming
Planned price: $29, once all chapters are built.
- All of Core
- Every Orgo 1 chapter
- All 3D stories & video walkthroughs
You will never be charged for anything you already received free. Refund terms are in our Refund policy.
Questions
Who is this for?
Students in Organic Chemistry 1 or 2, pre-med students, and anyone preparing for the organic-chemistry content in the MCAT. It follows the usual two-semester order, so it works alongside any textbook.
Is the content copied from a textbook or past exams?
No. Every problem, solution and drawing is original. Textbooks are used only to understand which topics students are expected to know, and no actual exam questions are reused.
How are the solutions checked?
Each set is solved twice and then checked separately for chemistry errors (names, stereochemistry, arrows, numbers). Structures are validated with cheminformatics software. We still make mistakes: if you find one, tell us and we will fix it.
Does AI write this?
AI tools are part of how we draft and format the material. The chemistry is reviewed and signed off by a chemistry teacher, and any AI-generated voice or video will always be labelled as such.
Is this affiliated with the MCAT, AAMC or a textbook publisher?
No. MCAT is a registered trademark of the Association of American Medical Colleges, which does not endorse USOrgo. We are independent of all textbook publishers.
Will you guarantee my grade?
No one can. This is practice material; results depend on the work you put in.
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