Learn
Step-by-step explainers for the questions that show up on every organic and general chemistry exam — written to be read once and remembered. Every post links to the whiteboard so you can try the drawing yourself.
How to draw a cyclohexane chair conformation
Step-by-step guide to drawing the cyclohexane chair, identifying axial vs equatorial positions, and doing a ring flip without losing track of substituents.
Read →Wedge and dash bonds: stereochemistry notation
What solid wedges, dashed wedges, and hashed wedges mean on a 2D structure, plus when to use each one.
Read →How to draw a benzene ring
The two correct ways to draw benzene — Kekulé alternating double bonds and the modern circle inside a hexagon — and when to use each.
Read →SN1 vs SN2: how to tell the difference
The four factors that decide whether a substitution goes by SN1 or SN2: substrate, nucleophile, solvent, and leaving group.
Read →E1 vs E2: elimination mechanisms
The differences between E1 and E2 elimination — kinetics, stereochemistry, regiochemistry, and which conditions favor each.
Read →How to spot a chirality center
The two-rule test for finding chiral carbons fast, plus the molecules students most often miss.
Read →R/S configuration: the CIP priority rules
How to assign R or S to a stereocenter using the Cahn–Ingold–Prelog priority rules, with the tricks for tied priorities.
Read →How to read a Fischer projection
Fischer projection rules: horizontal bonds come toward you, vertical bonds go away — plus how to convert to and from a 3D drawing.
Read →Newman projections: eclipsed vs staggered
How to draw and read a Newman projection, plus the energy differences between eclipsed, gauche, and anti conformations.
Read →Lewis structures and formal charge
Build any Lewis structure in five steps and use formal charge to pick between resonance forms — without memorization.
Read →Aromaticity and Hückel's rule
How to check whether a ring is aromatic using Hückel's rule (4n + 2 π electrons), plus the difference between aromatic, antiaromatic, and nonaromatic.
Read →sp, sp², sp³ hybridization
How to figure out the hybridization of any atom by counting groups, and what each hybridization means for bond angles and geometry.
Read →How to draw resonance structures
The arrow-pushing rules for resonance, the four types of allowed moves, and how to rank the contributors.
Read →Nucleophiles vs electrophiles
How to tell whether a species is a nucleophile or electrophile, and how strength tracks with charge, basicity, and polarizability.
Read →Ortho/meta/para directors in EAS
Which substituents on benzene direct an electrophile to the ortho/para positions and which direct to the meta — and why.
Read →Markovnikov vs anti-Markovnikov addition
Markovnikov's rule for alkene addition, the carbocation logic behind it, and when peroxides flip the regiochemistry.
Read →IUPAC nomenclature for alkanes
How to name any branched alkane in five steps using the IUPAC rules, with the prefixes and the numbering rule.
Read →Degrees of unsaturation
How to calculate degrees of unsaturation (the index of hydrogen deficiency) from a molecular formula, with rules for heteroatoms.
Read →IR spectroscopy functional groups
Reference table of IR stretching frequencies by functional group, with the tells students need to identify unknowns.
Read →NMR chemical shifts
Quick-reference table of ¹H and ¹³C NMR chemical shifts by environment, plus the tells for common functional groups.
Read →Skip the reading. Just draw.
The whiteboard is open right now. No account needed.