Learn Chemistry. Practice Chemistry. Master Chemistry.
Complete lessons, curated practice, chemistry diagrams, and printable resources—all organized by topic.
Featured learning paths
Build Your Foundation
Balance equations, calculate moles, understand bonding, and solve quantitative chemistry problems.
Start with stoichiometry →Understand Reaction Mechanisms
Learn substitution, elimination, stereochemistry, and why reaction conditions change products.
Explore reaction pathways →Interpret Real Chemistry Data
Learn IR, proton NMR and thin-layer chromatography through worked examples and practice.
Explore spectroscopy lessons →Explore by topic
Stoichiometry: A Step-by-Step Guide
Use balanced equations to convert between grams, moles and product amounts with a repeatable problem-solving process.
LessonPracticeReview
Significant Figures: Rules & Practice
Learn which digits count, how to round calculated results, and how to avoid the mistakes most students make.
LessonPracticeReview
Molarity: Formula, Examples & Calculator
Understand concentration, solve molarity problems step by step, and check your calculations with a free tool.
LessonPracticeReview
How to Balance Chemical Equations
Learn a repeatable method for balancing reactions without changing the chemical substances.
LessonPracticeReview
How to Write Ionic Compound Formulas
Use ion charges and the lowest whole-number ratio to write neutral ionic compounds with confidence.
LessonPracticeReview
How to Draw Lewis Structures
Count valence electrons, draw bonds, and check octets and formal charges.
LessonPracticeReview
VSEPR Molecular Geometry and Bond Angles
Predict shapes using bonding regions, central lone pairs, and electron-group geometry.
LessonPracticeReview
Limiting Reactant Problems: Step-by-Step
Identify which reagent runs out first and calculate theoretical product amount.
LessonPracticeReview
Gas Laws: Boyle, Charles, and the Ideal Gas Equation
Select a gas law, convert temperature to kelvin, and solve with correct units.
LessonPracticeReview
Periodic Trends: Atomic Radius, Ionization Energy, and Electronegativity
Understand why properties change across rows and down columns of the periodic table.
LessonPracticeReview
Solution Dilution: C₁V₁ = C₂V₂ Explained
Calculate how much stock solution to transfer when preparing a new concentration.
LessonPracticeReview
SN1 vs SN2 vs E1 vs E2: Choose the Pathway
Predict substitution or elimination by analyzing the substrate, reagent, solvent and reaction temperature together.
LessonPracticeReview
SN2 Stereochemistry: Inversion Explained
Learn what inversion means, why R does not always become S, and how to redraw products correctly.
LessonPracticeReview
E2 in Cyclohexanes: Trans-Diaxial Requirement
Understand why ring conformations control E2 elimination and how to recognize a productive chair.
LessonPracticeReview
IR Spectroscopy: Identify Functional Groups
Read wavenumber, bond vibrations, carbonyl and O–H bands; practice identifying functional groups.
LessonPracticeWorksheet
¹H NMR: Chemical Shift, Integration & Splitting
Interpret chemical shifts, integrals and simple n + 1 splitting using a real ethyl acetate example.
LessonPracticeWorksheet
Thin-Layer Chromatography: TLC & Rf Values
Understand normal-phase TLC, calculate Rf values and choose an effective solvent system.
LessonPracticeWorksheet
Organic Acid–Base Reactions: pKa & Equilibrium
Use conjugate acid strength and approximate pKa values to predict acid–base reaction direction.
LessonPracticeWorksheet
Alkene Addition Reactions: Predict the Product
Compare hydrohalogenation, hydration, bromination and hydroboration with predictable regiochemistry.
LessonPracticeWorksheet
Assigning R and S Configuration: A Visual Guide
Practice CIP priorities, viewpoint and the clockwise/counterclockwise rule for stereocenters.
LessonPracticeWorksheet
Alcohol Reactions
Use alcohol structure and reaction conditions to predict carbonyls, alkenes, and substitution products.
LessonPracticeWorksheet
Ether Synthesis
Learn why a primary electrophile and a strong alkoxide form an ether by an SN2 pathway.
LessonPracticeWorksheet
Epoxide Ring Opening
Predict which epoxide carbon is attacked and where the new C–Nu bond forms.
LessonPracticeWorksheet
Alkyne Reactions
Differentiate cis and trans partial reductions and predict terminal-alkyne hydration products.
LessonPracticeWorksheet
Radical Reactions
Understand radical chains, HBr peroxide regioselectivity, and selectivity in radical halogenation.
LessonPracticeWorksheet
Synthesis Roadmaps
Learn to plan transformations backward from the target molecule and verify each step.
LessonPracticeWorksheet
Aldehydes & Ketones
Recognize carbonyl groups, name simple compounds, and predict relative reactivity.
LessonPracticeWorksheet
Carbonyl Addition
Track nucleophile attack, the tetrahedral intermediate, and protonation or workup.
LessonPracticeWorksheet
Hemiacetals & Acetals
Learn why alcohol addition produces hemiacetals and how acidic conditions yield acetals.
LessonPracticeWorksheet
Imines & Enamines
Connect the choice of amine to C=N formation or alpha-carbon unsaturation.
LessonPracticeWorksheet
Carboxylic Acids & Esters
Understand acid structure, carboxylate stability, and equilibrium-driven ester synthesis.
LessonPracticeWorksheet
Acyl Substitution
Compare acid chlorides, anhydrides, esters and amides using the tetrahedral intermediate.
LessonPracticeWorksheetNo matching topics. Try a different search term or course.
Browse the free worksheet library →
New: Organic Chemistry Reaction Atlas
Six additional reaction lessons with verified condensed reaction diagrams, complete practice, and instructor-ready worksheets.
NEW: Carbonyl Chemistry Academy
Six complete lessons with original figures, 48 curated practice questions, and a searchable 24-reaction reference.
Explore Carbonyl Chemistry →