Test your knowledge
Test your knowledge with chemistry skill checks! Each skill check will recommend videos to help you brush up and learn more.
Skill check: Atoms and molecules (Exercise)
Skill check: Stoichiometry (Exercise)
Skill check: Electron configurations (Exercise)
Skill check: Periodic trends

Skill check for atoms, compounds, and ions
Want to check your knowledge of atoms and compounds for the new school year? Try a skill check for some quick review and links to related videos!
Skill check: Atoms and molecules (Exercise)
Introduction to the atom
In chemistry, we will often be thinking about the world on a much smaller scale than you can see with the naked eye. Here we will learn about atoms and elements, tiny particles that make up the world around us. What are atoms, and what kind of properties do they have? How do we weigh and count atoms? We will answer those questions in this section!
Elements and atoms (Video)
Atomic number, mass number, and isotopes (Video)
Isotopes and mass spectrometry (Article)
Atomic weight and atomic mass (Video)
Atomic weight (Video)
The mole and Avogadro's number (Video)
Compounds and ions
There are 118 elements on the periodic table, and often you will see them combine in specific ratios to form compounds. In this tutorial we will learn about the different ways that chemists represent, count, and categorize compounds.
Dalton's atomic theory (Article)
Molecules and compounds (Article)
Empirical, molecular, and structural formulas (Video)
Molecular mass and molecular weight (Video)
Naming monatomic ions and ionic compounds (Article)
Common polyatomic ions (Video)
Polyatomic ions
Skill check for chemical reactions and stoichiometry
Want to check your knowledge of chemical reactions and stoichiometry for the new school year? Try a skill check for some quick review and links to related videos!
Skill check: Stoichiometry (Exercise)
Balancing chemical equations
We are now going to look at chemical reactions. But as we do, we need to make sure that atoms aren't magically appearing or disappearing. Put another way, we need to sure that we have the same number of each constituent atom in the product of the reaction as we do in the reactants (the molecules that react)!
Chemical reactions introduction (Video)
Balancing chemical equations (Video)
Balancing more complex chemical equations (Video)
Visually understanding balancing chemical equations (Video)
Balancing another combustion reaction (Video)
Balancing chemical equation with substitution (Video)
Balancing Chemical Equations Intuition (Scratchpad)
Balancing chemical equations 1 (Exercise)
Complete ionic and net ionic equations (Article)
Stoichiometry
Now we are going to draw the connections between balancing equations and what happens in the lab (where you actually have a certain mass of a compound).
Stoichiometry (Article)
Stoichiometry (Video)
Stoichiometry example problem 1 (Video)
Stoichiometry example problem 2 (Video)
Ideal stoichiometry (Exercise)
Limiting reagent stoichiometry
In a reaction, you often have extra of one molecule (or too little of the other) so all the reactant doesn't react. We'll explore how to identify which reactant is limiting which is helpful in a whole series of scenarios.
Stoichiometry: Limiting reagent (Video)
Limiting reactant example problem 1 (Video)
Limiting reagent stoichiometry (Exercise)
Limiting reagents and percent yield (Article)
Introduction to gravimetric analysis: Volatilization gravimetry (Article)
Gravimetric analysis and precipitation gravimetry (Article)
Molecular composition
We'll now explore two different ways of representing what elements are in a molecule: molecular and empirical formulas. Then we'll actually Molecular formulas actually represent the number of atoms in a molecule while empirical formulas show us the ratio of the constituents based on experiments. In order to help us connect these ideas, we'll also explore a quantity called the "mole". Just as a "dozen" represents 12 of something, a "mole" represents roughly 602,200,000,000,000,000,000,000 of something. This will help us think about mass composition of molecules.
Empirical, molecular, and structural formulas (Video)
Molecular mass percentage (Video)
Molecular weight percentages (Video)
Empirical formula from mass composition (Video)
Another mass composition problem (Video)
Types of chemical reactions
Introduction to redox reactions (Video)
Oxidation number (Article)
Oxidation-reduction (redox) reactions (Article)
Dissolution and precipitation (Video)
Double replacement reactions (Article)
Single replacement reactions
Skill checks for electronic structure of atoms
Want to check your knowledge of electronic structure? Try a skill check for some quick review and links to related videos!
Skill check: Electron configurations (Exercise)
History of atomic structure
How did scientists figure out the structure of the atom, and how did they discover subatomic particles? The answer is X-ray vision (just kidding!). In this section, we will discuss some of the awesome experiments in science history that led to our modern understanding of atomic structure.
The history of atomic chemistry (Video)
Dalton's atomic theory (Article)
Discovery of the electron and nucleus (Article)
Rutherford’s gold foil experiment (Video)
Bohr's model of hydrogen (Article)
Bohr's model of the hydrogen atom
Atomic theory is not Bohr-ing! While it doesn't work for atoms with more than one electron, the Bohr model successfully predicts the emission spectrum of hydrogen.
Light: Electromagnetic waves, the electromagnetic spectrum and photons (Article)
Introduction to light (Video)
Spectroscopy: Interaction of light and matter (Article)
Photoelectric effect (Video)
Photoelectric effect (Article)
Bohr's model of hydrogen (Article)
Bohr model radii (derivation using physics) (Video)
Bohr model radii (Video)
Bohr model energy levels (derivation using physics) (Video)
Bohr model energy levels (Video)
Absorption and emission (Video)
Emission spectrum of hydrogen (Video)
Quantum numbers and orbitals
In this tutorial, we will see how the quantum numbers predict the orbitals available in different energy levels.
Heisenberg uncertainty principle (Video)
Quantum numbers (Video)
Quantum numbers for the first four shells (Video)
Electron configurations
In this tutorial, Sal and Jay show how to write electron configurations.
Orbitals (Video)
More on orbitals and electron configuration (Video)
Noble gas configuration (Video)
Electron configurations 2 (Video)
Electron configurations for the first period (Video)
Electron configurations for the second period (Video)
Electron configurations for the third and fourth periods (Video)
Electron configuration for d block element (Video)
Electron configurations in the 3d orbitals (Video)
Electron configuration for f block element Nd (Video)
Paramagnetism and diamagnetism
Skill checks for the periodic table
Want to check your knowledge of the periodic table? Try a skill check for some quick review and links to related videos!
Skill check: Periodic trends (Exercise)
Introduction to the periodic table
How are the elements organized in the periodic table? This tutorial will cover the classification of elements including groups, transition metals, and valence electrons.
The periodic table – classification of elements (Video)
Groups of the periodic table (Video)
The periodic table – valence electrons for main group (Video)
The periodic table – transition metals (Video)
Valence electrons and bonding (Video)
Periodic table trends
Have you ever wondered why it is called the "periodic" table? The elements are organized based on their electronic structure, which results in some interesting trends in atomic properties as you move down a group or across a period. This tutorial will try to explain some of those trends!
Atomic radius trends on periodic table (Video)
Atomic and ionic radii (Video)
Mini-video on ion size (Video)
Ionization energy trends (Video)
Group trend for ionization energy (Video)
Period trend for ionization energy (Video)
First and second ionization energy (Video)
Electron affinity (Video)
Period trend for electron affinity (Video)
Electronegativity (Video)
Electronegativity and bonding (Video)
Metallic nature
Types of chemical bonds
In this tutorial, we will learn about electronegativity and the different types of chemical bonds.
Ionic, covalent, and metallic bonds (Video)
Electronegativity (Video)
Electronegativity and bonding (Video)
Metallic nature (Video)
Covalent networks, metallic crystals, and ionic crystals (Video)
Dot structures and molecular geometry
We can’t always see molecules, but we can always simplify and draw depictions of them with pen and paper. It is the language of chemistry that we want you to get acquainted with. You will learn to draw Lewis dot structures and resonance structures, assign formal charges, and analyze the geometry of molecules and ions using VSEPR theory.
Drawing dot structures (Video)
Formal charge and dot structures (Video)
Resonance and dot structures (Video)
VSEPR for 2 electron clouds (Video)
VSEPR for 3 electron clouds (Video)
More on the dot structure for sulfur dioxide (Video)
VSEPR for 4 electron clouds (Video)
VSEPR for 5 electron clouds (Video)
VSEPR for 5 electron clouds (continued) (Video)
VSEPR for 6 electron clouds (Video)
Dipole moment (Video)
Hybridization and hybrid orbitals
In this tutorial, we will learn about sp3, sp2, and sp hybridization.
Sp3 hybridization (Video)
Steric number and sp3 hybridization (Video)
Sp2 hybridization (Video)
Sp hybridization (Video)
Organic hybridization practice
Ideal gas equation
In this tutorial, Sal shows you how to use the ideal gas equation in calculations.
Ideal gas equation: PV = nRT (Video)
Deflate gate (Video)
Ideal gas equation example 1 (Video)
Ideal gas equation example 2 (Video)
Ideal gas equation example 3 (Video)
Ideal gas equation example 4 (Video)
Partial pressure example (Video)
Vapor pressure example (Video)
Maxwell Boltzmann distribution (Video)
Non-ideal behavior of gases
States of matter
States of matter (Video)
States of matter follow-up (Video)
Specific heat and latent heat of fusion and vaporization (Video)
Specific heat, heat of fusion and vaporization example (Video)
Chilling water problem (Video)
Change of state example (Video)
Vapor pressure (Video)
Phase diagrams (Video)
Introduction to intermolecular forces
Van der Waals forces (Video)
Solubility and intermolecular forces (Video)
Surface tension (Video)
Capillary action and why we see a meniscus (Video)
Mixtures and solutions
Molarity (Article)
Suspensions, colloids and solutions (Video)
Boiling point elevation and freezing point depression
Equilibrium constant
In this tutorial, we will examine the equilibrium state and learn how to write the expression for the equilibrium constant.
Reactions in equilibrium (Video)
Keq intuition (mathy and not necessary to progress) (Video)
Keq derivation intuition (can skip; bit mathy) (Video)
Heterogeneous equilibrium (Video)
Factors that affect chemical equilibrium
In this tutorial, we will learn about the different factors that affect a reaction mixture at equilibrium.
Le Chatelier's principle (Video)
The reaction quotient Q
Acids, bases, and pH
What makes a compound acidic or basic? We will learn about the different definitions for acids and bases, and how we measure how acidic or basic a substance is. We will be putting our chemical equilibrium knowledge to good use when we look at the reactivity of weak acids and bases.
Arrhenius definition of acids and bases (Video)
Bronsted-Lowry definition of acids and bases (Video)
Autoionization of water (Video)
Definition of pH (Video)
pH, pOH of strong acids and bases (Video)
Acid-base equilibria
In this tutorial, we will learn how the strength of an acid or base is related to the equilibrium reaction that is happening in our solution. We will also see what happens when we mix solutions of acids and bases in neutralization reactions.
Conjugate acids and bases (Video)
pKa and pKb relationship (Video)
Relationship between Ka and Kb (Video)
Weak acid equilibrium (Video)
Weak base equilibrium (Video)
Acid-base properties of salts (Video)
pH of salt solutions
Buffer solutions
Buffer solutions play an important role in many chemical and biological processes. In this tutorial we will learn how buffers resist changes in pH, and how to calculate the pH of a buffer solution.
Introduction to buffers (Video)
Common ion effect and buffers (Video)
Buffers and Henderson-Hasselbalch (Video)
Buffer solution pH calculations (Video)
Titrations
Chemists use titrations to determine the concentration of an acid, base, or other substance in solution. We will cover the different types (strong acid/strong base, strong acid/weak base, weak acid/strong base, and redox), calculating the pH at different points of the titration, and choosing indicators.
Titration introduction (Video)
Titration calculation example (Video)
Titration of a strong acid with a strong base (Video)
Titration of a strong acid with a strong base (continued) (Video)
Titration of a weak acid with a strong base (Video)
Titration of a weak acid with a strong base (continued) (Video)
Titration of a weak base with a strong acid (Video)
Titration of a weak base with a strong acid (continued) (Video)
Titration curves and acid-base indicators (Video)
Titration roundup (Video)
Acid base titration example (Video)
Redox titration (Video)
Solubility equilibria
In this tutorial we will learn how to think about the solubility and precipitation of ionic compounds in the context of chemical equilibrium. We will also look at different factors that can affect the solubility such as pH and the formation of complex ions.
Dissolution and precipitation (Video)
Common polyatomic ions (Video)
Solubility product constant from the solubility (Video)
Solubility from the solubility product constant (Video)
Solubility and the common-ion effect (Video)
Solubility and the pH of the solution (Video)
Solubility and complex ion formation
nternal energy
An introduction to the first law of thermodynamics, internal energy, heat, work, and PV diagrams
Macrostates and microstates (Video)
Quasistatic and reversible processes (Video)
First law of thermodynamics / internal energy (Video)
More on internal energy (Video)
Heat and temperature (Article)
Pressure-volume work (Article)
Work from expansion (Video)
PV-diagrams and expansion work (Video)
Enthalpy
An introduction to enthalpy and Hess's law
Enthalpy (Video)
Heat of formation (Video)
Hess's law and reaction enthalpy change (Video)
Hess's law example (Video)
Bond enthalpy and enthalpy of reaction (Article)
Entropy
An introduction to the Carnot cycle and entropy
Entropy: Embrace the chaos (Video)
Work done by isothermic process (Video)
Carnot cycle and Carnot engine (Video)
Proof: Volume ratios in a carnot cycle (Video)
Proof: S (or entropy) is a valid state variable (Video)
Thermodynamic entropy definition clarification (Video)
Reconciling thermodynamic and state definitions of entropy (Video)
Entropy intuition (Video)
Maxwell's demon (Video)
More on entropy (Video)
Gibbs free energy
An introduction to Gibbs free energy and how free energy relates to spontaneity and the equilibrium constant
Gibbs free energy and spontaneity (Video)
Gibbs free energy and spontaneity (Article)
Gibbs free energy example (Video)
More rigorous Gibbs free energy / spontaneity relationship (Video)
A look at a seductive but wrong Gibbs/spontaneity proof (Video)
Changes in free energy and the reaction quotient (Video)
Standard change in free energy and the equilibrium constant
Oxidation-reduction reactions
Oxidation and reduction are powerful ideas for thinking about how charge is transferred within a reaction. As we'll see, it is something of a hypothetical, but it is, nonetheless, very useful.
Oxidation and reduction (Video)
Oxidation state trends in periodic table (Video)
Practice determining oxidation states (Video)
Unusual oxygen oxidation states (Video)
Introduction to redox reactions (Video)
Redox reaction with iron (Video)
Oxidizing and reducing agents (Video)
Disproportionation (Video)
Balancing redox reactions in acid (Video)
Balancing redox reactions in base (Video)
Redox titration (Video)
Galvanic cells
Batteries power much of our lives (literally). In this tutorial, we'll use our knowledge of oxidation and reduction to understand how Galvanic/Voltaic cells actually work.
Redox reaction from dissolving zinc in copper sulfate (Video)
Introduction to galvanic/voltaic cells (Video)
Electrodes and voltage of Galvanic cell (Video)
Shorthand notation for galvanic/voltaic cells (Video)
Lead storage battery (Video)
Nickel-cadmium battery (Video)
Standard cell potentials
An introduction to calculating cell potentials at standard state.
Standard reduction potentials (Video)
Using reduction potentials (Video)
Voltage as an intensive property (Video)
Spontaneity and redox reactions (Video)
Electrochemistry, thermodynamics, and equilibrium
Relating the cell potential to the equilibrium constant K and Gibbs free energy.
Free energy and cell potential (Video)
Standard cell potential and the equilibrium constant (Video)
Calculating the equilibrium constant from the standard cell potential (Video)
Cell potentials under nonstandard conditions
Calculating the cell potential when operating at nonstandard conditions.
Galvanic cells and changes in free energy (Video)
Nernst equation (Video)
Using the Nernst equation (Video)
Concentration cell (Video)
Electrolytic cells and electrolysis
An introduction to electrolytic cells and electrolysis
Introduction to electrolysis (Video)
Quantitative electrolysis (Video)
Electrolysis of molten sodium chloride
Reaction rates and rate laws
In this tutorial, we will examine the rates of chemical reactions and learn how to write rate laws.
Introduction to kinetics (Video)
Rate of reaction (Video)
Rate law and reaction order (Video)
Experimental determination of rate laws (Video)
Relationship between reaction concentrations and time
In this tutorial, we will convert rate laws into equations that allow us to determine the concentrations of reactants at any time during the course of a reaction.
First-order reaction (with calculus) (Video)
Plotting data for a first-order reaction (Video)
Half-life of a first-order reaction (Video)
Half-life and carbon dating (Video)
First-order reaction example (Video)
Second-order reaction (with calculus) (Video)
Plotting data for a second-order reaction (Video)
Half-life of a second-order reaction (Video)
Second-order reaction example (Video)
Zero-order reaction (with calculus) (Video)
Arrhenius equation and reaction mechanisms
In this tutorial, we will learn about reaction mechanisms and how temperature and the activation energy affect the rate of a reaction.
Collision theory (Video)
Arrhenius equation (Video)
Forms of the Arrhenius equation (Video)
Using the Arrhenius equation (Video)
Maxwell Boltzmann distribution (Video)
Elementary rate laws (Video)
Mechanisms and the rate-determining step (Video)
Catalysts (Video)
Spectrophotometry
In the lab, it is useful to know how much of something you have or the concentration of a solute. In this tutorial, we'll light to do that!
Spectrophotometry introduction (Video)
Spectrophotometry example
Radioactive decay
Mass defect and binding energy (Video)
Nuclear stability and nuclear equations (Video)
Types of decay (Video)
Writing nuclear equations for alpha, beta, and gamma decay (Video)
Half-life and carbon dating (Video)
Half-life plot (Video)
Exponential decay formula proof (can skip, involves calculus) (Video)
Introduction to exponential decay (Video)
More exponential decay examples (Video)
Exponential decay and semi-log plots
Meet the chemistry professional
We've invited professionals from all kinds of careers to share their stories. What do all these people have in common? They all studied chemistry! Find out how chemistry can be used in everything from engineering to making TV shows.
Introduction to "Meet a chemistry professional" (Video)
Syud Momtaz Ahmed, industrial scientist and tabla player (Article)
Andrew Chadeayne, inventor and coonhound trainer (Article)
Colin Fuller, software engineer and outdoor enthusiast (Article)
Mary O'Reilly, science illustrator and comic strip writer (Article)
Rachel Price, engineer and bike-traveler (Article)
Jared Roop, forensics/analytical chemist and Cardinals fan (Article)
Monica Shah, epidemiologist and bicyclist (Article)
Karen Wheeler, physician and long distance runner (Article)
George Zaidan, science media jack-of-all-trades and rock climber
Explanations
Calling great explainers of the world! Help us answer frequently asked chemistry questions by writing clear, deep, engaging explanations. Your explanation may even be selected for an article on Khan Academy (with full credit to you)!
What are community explanations? (Article)
What is a mole? (Scratchpad)
What is an orbital? (Scratchpad)
What is a buffer, and how can you make one? (Scratchpad)
What are titrations used for? (Scratchpad)
When writing electron configurations for transition metals, why does the 4s subshell fill before the 3d subshell? (Scratchpad)
In chemistry, what is a state function?
Ask a chemist! (Archived)
Ask a chemist! (archived)
Dot structures
Going dotty trying to review? Don't worry about a single thing – or multiples for that matter! Get some points on simple organic dot structures in this tutorial.
Dot structures I: Single bonds (Video)
Dot structures II: Multiple bonds (Video)
Hybridization
How closely bonded are you to your idea of orbitals? In this tutorial, we will learn about hybridized orbitals, the ligers of organic chemistry.
sp3 hybridized orbitals and sigma bonds (Video)
Pi bonds and sp2 hybridized orbitals (Video)
Sp3 hybridization (Video)
Steric number and sp3 hybridization (Video)
Sp2 hybridization (Video)
Sp hybridization (Video)
Organic hybridization practice (Video)
Tetrahedral bond angle proof (Video)
Bond-line structures
Call them Bonds. Covalent Bonds. Smart chemists need time to stir (and shake) their solutions. In this tutorial, we will explain how chemists use bond-line structures as a form of organic shorthand to skip time-consuming carbon and hydrogen atoms labeling. Watch this tutorial so you too can be in the Dr. Know.
Condensed structures (Video)
Bond-line structures (Video)
Three-dimensional bond-line structures (Video)
Structural (constitutional) isomers (Video)
Electronegativity
What is the most attractive concept in undergraduate organic chemistry? Currently most are polarized on the topic, but the pull of electronegativity is hard to resist. Within this tutorial, we will learn about electronegativity and see how it applies to polarity, intermolecular forces, and physical properties.
Electronegativity and bonding (Video)
Dipole moment (Video)
Intermolecular forces (Video)
Boiling points of organic compounds (Video)
Solubility of organic compounds
Counting electrons
Aspiring chemists need to be able to count electrons. Without this ability, your days as a chemist would be numbered. In this tutorial, you will learn how to count electrons to assign formal charges and oxidation states. Both forms of "electron bookkeeping" are important concepts to understand for organic reactions.
Comparing formal charges to oxidation states (Video)
Formal charge on carbon (Video)
Formal charge on nitrogen (Video)
Formal charge on oxygen (Video)
Oxidation states of carbon (Video)
Organic oxidation-reduction reactions (Video)
Resonance structures
Are bond-line drawings not resonating with you? Sometimes one drawing is not enough to accurately describe the distribution of electron density. In this tutorial, we will learn how two or more resonance structures are merged to give us a single representation (a resonance hybrid).
Resonance structures (Video)
Resonance structure patterns (Video)
Resonance structures for benzene and the phenoxide anion (Video)
Common mistakes when drawing resonance structures (Video)
Resonance structures and hybridization (Video)
Organic acid-base chemistry
Do you remember the basics of acid-base chemistry? If your answer is neutral, then you might want to watch this tutorial and review these important concepts from general chemistry.
Acid-base definitions (Video)
Organic acid-base mechanisms (Video)
Ka and acid strength (Video)
Ka and pKa review (Video)
Using a pKa table (Video)
Using pKa values to predict the position of equilibrium (Video)
Stabilization of a conjugate base: electronegativity (Video)
Acid strength, anion size, and bond energy (Video)
Stabilization of a conjugate base: resonance (Video)
Stabilization of a conjugate base: induction (Video)
Stabilization of a conjugate base: hybridization (Video)
Stabilization of a conjugate base: solvation
Naming alkanes
Methane, ethane, propane, butane . . . by the time you get to five carbons you might have some pent up frustration. By six carbons you might even believe that you are hexed! Don’t worry though, you’ll feel sane again once Sal shows you how to name alkanes in this tutorial.
Representing structures of organic molecules (Video)
Naming simple alkanes (Video)
Naming alkanes with alkyl groups (Video)
Correction – 2-propylheptane should never be the name! (Video)
Common and systematic naming: iso-, sec-, and tert- prefixes (Video)
Naming alkanes with ethyl groups (Video)
Alkane with isopropyl group (Video)
Organic chemistry naming examples 2 (Video)
Organic chemistry naming examples 3 (Video)
Naming a cycloalkane (Video)
Naming two isobutlyl groups systematically (Video)
Organic chemistry naming examples 5 (Video)
Naming alkanes, cycloalkanes, and bicyclic compounds
Do you speak the language of organic chemistry? Nomenclature running rings around you? Feel like the victim of a vicious cycle? In this tutorial, we will learn how to be fluent in naming alkanes, cycloalkanes, and bicyclic compounds.
Alkane and cycloalkane nomenclature I (Video)
Alkane and cycloalkane nomenclature II (Video)
Alkane and cycloalkane nomenclature III (Video)
Bicyclic compounds (Video)
Naming cubane (Video)
Heats of combustion of alkanes (Video)
Conformations of alkanes
Feeling unsure about conformations? If you need a little more perspective on alkanes, try looking at them from Newman’s point of view. The result might leave you feeling more stable.
Newman projections (Video)
Newman projections 2 (Video)
Conformations of ethane (Video)
Conformational analysis of ethane (Video)
Conformational analysis of propane (Video)
Conformational analysis of butane (Video)
Newman projection practice 1 (Video)
Newman projection practice 2 (Video)
Conformations of cycloalkanes
Do conformations float your boat? If so, pull up a chair and learn about the different conformations of cyclohexane.
Chair and boat shapes for cyclohexane (Video)
Double Newman diagram for methylcyclohexane (Video)
Stability of cycloalkanes (Video)
Conformations of cyclohexane (Video)
Drawing chair conformations (Video)
Monosubstituted cyclohexane (Video)
Disubstituted cyclohexane (Video)
Polysubstituted cyclohexane (Video)
Functional groups
The chemistry of every organic compound is determined by the functional groups it contains. In this tutorial, we put the fun back into identifying functional groups!
Functional groups (Video)
More functional groups (Video)
Identifying functional groups
Chirality
Are you right handed or sinister-handed? Have you ever thought that you might not be as attractive as you look in the mirror? Welcome to the world of chirality!
Introduction to chirality (Video)
Chiral examples 1 (Video)
Chiral examples 2 (Video)
Chiral vs achiral (Video)
Stereoisomers, enantiomers, and chirality centers (Video)
Identifying chirality centers (Video)
Enantiomers
In this tutorial, we will explore enantiomers, compounds that have the same composition and bonding but are fundamentally different because they are mirror images of each other (kind of like Tomax and Xamot–the Crimson Guard Commanders from GI Joe).
Drawing enantiomers (Video)
Cahn-Ingold-Prelog system for naming enantiomers (Video)
R,S system (Video)
R,S (Cahn-Ingold-Prelog) naming system example 2 (Video)
R,S system practice (Video)
More R,S practice (Video)
Fischer projection introduction (Video)
Fischer projection practice (Video)
Optical activity (Video)
Optical activity calculations (Video)
Stereoisomeric relationships
Mirror, mirror on the wall . . . who is the fairest stereoisomer of all? In this tutorial, we will examine the relationships between different stereoisomers.
Stereoisomers, enantiomers, diastereomers, constitutional isomers and meso compounds (Video)
Enantiomers and diastereomers (Video)
Meso compounds
Free radical reaction
In this tutorial, Sal introduces free radical reactions by showing the reaction of methane with chlorine.
Free radical reactions (Video)
Sn1 vs Sn2
In this tutorial, Sal analyzes the differences between SN1 and SN2 reactions.
Naming alkyl halides (Video)
Curly arrow conventions in organic chemistry (Video)
Sn2 reactions (Video)
Sn1 reactions introduction (Video)
Steric hindrance (Video)
Sn2 stereochemistry (Video)
Sn1 and Sn2 solvents effects (Video)
Nucleophilicity and basicity
In this tutorial, Sal discusses the difference between nucleophilicity and basicity.
Nucleophilicity (nucleophile strength) (Video)
Nucleophilicity vs. basicity (Video)
Elimination reactions
In this tutorial, Sal explains the difference between an E1 and an E2 elimination reaction.
E2 reactions (Video)
E1 reactions (Video)
Zaitsev's rule (Video)
Sn1/Sn2/E1/E2
In this tutorial, Sal compares the differences between SN1, SN2, E1, and E2 reactions.
Comparing E2, E1, Sn2, Sn1 reactions (Video)
E2 E1 Sn2 Sn1 reactions example 2 (Video)
E2 E1 Sn2 Sn1 reactions example 3 (Video)
Sn1 and Sn2
In this tutorial, Jay covers the definitions of nucleophile/electrophile, The Schwartz Rules (may the Schwartz be with you!), and the differences between SN1 and SN2 reactions.
Nucleophile/electrophile and the schwartz rules (Video)
Alkyl halide nomenclature (Video)
Sn1 reaction: Mechanism (Video)
Sn1 reaction: Stereochemistry (Video)
Sn2 mechanism and stereochemistry (Video)
Sn1 vs Sn2: Solvent effects (Video)
Sn1 vs Sn2: Summary (Video)
E1 and E2 reactions
In this tutorial, Jay covers the E1 elimination mechanism, carbocation rearrangements, and the details of the E2 elimination reaction.
E1 elimination: Mechanism (Video)
E1 elimination: Regioselectivity and stereoselectivity (Video)
Carbocations and rearrangements (Video)
E2 elimination: Mechanism (Video)
E2 elimination: Regioselectivity (Video)
E2 elimination: Stereoselectivity (Video)
E2 elimination: Stereospecificity (Video)
E2 elimination: Substituted cyclohexanes (Video)
Sn1/Sn2/E1/E2
In this tutorial, Jay discusses the strength of a nucleophile and the differences between SN1, SN2, E1, and E2 reactions.
Nucleophilicity and basicity (Video)
Sn1 Sn2 E1 E2 reactions: Primary and tertiary alkyl halides (Video)
Sn1 Sn2 E1 E2 reactions: Secondary alkyl halides
Naming alkenes
In this tutorial, Sal names alkenes and discusses the E-Z system.
Naming alkenes examples (Video)
cis-trans and E-Z naming scheme for alkenes (Video)
Entgegen-Zusammen naming scheme for alkenes examples (Video)
Alkene reactions
In this tutorial, Sal shows several reactions of alkenes.
Introduction to reaction mechanisms (Video)
Markovnikov's rule and carbocations (Video)
Addition of water (acid-catalyzed) mechanism (Video)
Polymerization of alkenes with acid (Video)
Alkene nomenclature
In this tutorial, Jay names alkenes, discusses the stability of alkenes, and introduces the E/Z system.
Alkene intro and stability (Video)
Alkene nomenclature (Video)
Cis-trans isomerism (Video)
E-Z system (Video)
Alkene reactions
In this tutorial, Jay explains the addition reactions of alkenes.
Hydrogenation (Video)
Hydrohalogenation (Video)
Hydration (Video)
Hydroboration-oxidation (Video)
Hydroboration-oxidation: mechanism (Video)
Halogenation (Video)
Halohydrin formation (Video)
Epoxide formation and anti dihydroxylation (Video)
Syn dihydroxylation (Video)
Ozonolysis (Video)
Naming and preparing alkynes
In this tutorial, Jay covers the nomenclature and preparation of alkynes, the acidity of terminal alkynes, and the alkylation of alkynes.
Alkyne nomenclature (Video)
Alkyne acidity and alkylation (Video)
Preparation of alkynes (Video)
Alkyne reactions
In this tutorial, Jay shows the reactions of alkynes.
Reduction of alkynes (Video)
Hydrohalogenation of alkynes (Video)
Hydration of alkynes (Video)
Hydroboration-oxidation of alkynes (Video)
Halogenation and ozonolysis of alkynes (Video)
Synthesis using alkynes
In this tutorial, Jay demonstrates how to use Dr. Schwartz's organic flowsheet to solve synthesis problems involving alkynes. Always remember, pain is temporary, orgo is forever!
Synthesis using alkynes
Alcohol nomenclature and properties
It can clean a wound or kill your liver. Some religions ban it, others use it in their sacred rites. Some of the most stupid acts humanity every committed were done under its influence. It is even responsible for some of our births. In this tutorial, Sal and Jay name alcohols and discuss their properties.
Alcohols (Video)
Triple bonds cause linear configurations (Video)
Alcohol properties (Video)
Alcohol nomenclature (Video)
Physical properties of alcohols and preparation of alkoxides (Video)
Synthesis of alcohols
In this tutorial, Jay shows how to synthesize alcohols using sodium borohydride, lithium aluminum hydride, and grignard reagents.
Preparation of alcohols using NaBH4 (Video)
Preparation of alcohols using LiAlH4 (Video)
Synthesis of alcohols using Grignard reagents I (Video)
Synthesis of alcohols using Grignard reagents II (Video)
Reactions of alcohols
In this tutorial, Jay assigns oxidation states to alcohols, shows an oxidation mechanism using the Jones reagent, shows the formation of nitrate esters from alcohols, and demonstrates how to make alkyl halides from alcohols. Biochemical redox reactions are also discussed.
Oxidation of alcohols I: Mechanism and oxidation states (Video)
Oxidation of alcohols II: Examples (Video)
Biological redox reactions (Video)
Protection of alcohols (Video)
Preparation of mesylates and tosylates (Video)
SN1 and SN2 reactions of alcohols (Video)
Formation of nitrate esters (Video)
Preparation of alkyl halides from alcohols (Video)
Nomenclature and properties of ethers
In this tutorial, Sal and Jay name ethers and discuss the physical properties of ethers.
Ether naming and introduction (Video)
Ether nomenclature (Video)
Properties of ethers and crown ethers (Video)
Synthesis and cleavage of ethers
In this tutorial, Jay shows how to synthesize ethers using the Williamson ether synthesis and how to cleave an ether linkage using acid.
Williamson ether synthesis (Video)
Acidic cleavage of ethers (Video)
Nomenclature and preparation of epoxides
In this tutorial, Sal and Jay name epoxides. Jay also shows the preparation of epoxides and includes the stereochemistry of the reaction.
Cyclic ethers and epoxide naming (Video)
Nomenclature and preparation of epoxides (Video)
Preparation of epoxides: Stereochemistry (Video)
Ring-opening reactions of epoxides
In this tutorial, Sal and Jay show the SN1 and SN2 ring opening reactions of epoxides.
Ring-opening reactions of epoxides: Strong nucleophiles (Video)
Ring opening reactions of epoxides: Acid-catalyzed (Video)
Thiols and sulfides
In this tutorial, Jay shows how to prepare sulfides from thiols.
Preparation of sulfides
Diels-Alder reaction
What’s the big deal? Actually, the Diels-Alder reaction is a very big “diel” because it is commonly used in organic synthesis. Learn how to “diel” with this classic reaction in this tutorial.
Diels-Alder reaction (Video)
Diels-Alder: stereochemistry of dienophile (Video)
Diels-Alder: stereochemistry of diene (Video)
Diels-Alder: endo rule (Video)
Diels-Alder: intramolecular (Video)
Diels-Alder: regiochemistry
Naming benzene derivatives
Would a cyclohexatriene by any other name smell as sweet? In this tutorial, Sal and Jay explain how to name benzene derivatives, the sometimes sweet-smelling cyclic molecules that can be used in the synthesis of explosives and plastics.
Naming benzene derivatives introduction (Video)
Naming benzene derivatives (Video)
Reactions of benzene
In this tutorial, Sal shows the mechanism of Electrophilic Aromatic Substitution and the reactions of bromination and Friedel-Crafts Acylation.
Resonance (Video)
Electrophilic aromatic substitution (Video)
Bromination of benzene (Video)
Friedel crafts acylation (Video)
Friedel crafts acylation addendum (Video)
Aromatic stability
In this tutorial, Sal and Jay explain the concept of aromatic stabilization and show how to determine if a compound or an ion exhibits aromaticity. Knowledge of MO theory is assumed.
Aromatic stability I (Video)
Aromatic stability II (Video)
Aromatic stability III (Video)
Aromatic stability IV (Video)
Aromatic stability V (Video)
Aromatic heterocycles I (Video)
Aromatic heterocycles II (Video)
Electrophilic aromatic substitution
In this tutorial, Jay shows several electrophilic aromatic substitution reactions.
Electrophilic aromatic substitution mechanism (Video)
Halogenation (Video)
Nitration (Video)
Sulfonation (Video)
Friedel-Crafts alkylation (Video)
Friedel-Crafts acylation (Video)
Directing effects
In this tutorial, Jay shows you the directing effects of substituents on a benzene ring. Knowledge of Electrophilic Aromatic Substitution reactions is assumed.
Ortho-para directors I (Video)
Ortho-para directors II (Video)
Ortho-para directors III (Video)
Meta directors I (Video)
Meta directors II (Video)
Multiple substituents (Video)
Other reactions and synthesis
In this tutorial, Jay covers a few more reactions of benzene derivatives and also shows how to approach the synthesis of substituted benzene rings.
Birch reduction I (Video)
Birch reduction II (Video)
Reactions at the benzylic position (Video)
Synthesis of substituted benzene rings I (Video)
Synthesis of substituted benzene rings II (Video)
Nucleophilic aromatic substitution
In this tutorial, Jay shows the addition-elimination mechanism and the elimination-addition mechanism.
Nucleophilic aromatic substitution I (Video)
Nucleophilic aromatic substitution II
Introduction to aldehydes and ketones
In this tutorial, Sal and Jay show you the nomenclature, physical properties, and reactivity of aldehydes and ketones.
Aldehyde introduction (Video)
Ketone naming (Video)
Nomenclature of aldehydes and ketones (Video)
Physical properties of aldehydes and ketones (Video)
Reactivity of aldehydes and ketones (Video)
Reactions of aldehydes and ketones
In this tutorial, Jay shows you how to predict the products of the reactions of aldehydes and ketones.
Formation of hydrates (Video)
Formation of hemiacetals (Video)
Acid and base catalyzed formation of hydrates and hemiacetals (Video)
Formation of acetals (Video)
Acetals as protecting groups and thioacetals (Video)
Formation of imines and enamines (Video)
Formation of oximes and hydrazones (Video)
Addition of carbon nucleophiles to aldehydes and ketones (Video)
Formation of alcohols using hydride reducing agents (Video)
Oxidation of aldehydes using Tollens' reagent
Naming carboxylic acids
In this tutorial, Sal shows how to name carboxylic acids.
Carboxylic acid introduction (Video)
Carboxylic acid naming (Video)
Formation of carboxylic acid derivatives
In this tutorial, Sal shows the formation of carboxylic acid derivatives including esters, acyl chlorides, and amides.
Fischer esterification (Video)
Acid chloride formation (Video)
Amides, anhydrides, esters, and acyl chlorides (Video)
Relative stability of amides, esters, anhydrides, and acyl chlorides (Video)
Amide formation from acyl chloride (Video)
Nomenclature and reactions of carboxylic acids
In this tutorial, Jay shows you how to name carboxylic acids and the products of different reactions of carboxylic acids.
Carboxylic acid nomenclature and properties (Video)
Reduction of carboxylic acids (Video)
Preparation of acyl (acid) chlorides (Video)
Preparation of acid anhydrides (Video)
Preparation of esters via Fischer esterification (Video)
Preparation of amides using DCC (Video)
Decarboxylation (Video)
Nomenclature and reactions of carboxylic acid derivatives
In this tutorial, Jay shows you the nomenclature, properties, and reactions of carboxylic acid derivatives.
Nomenclature and properties of acyl (acid) halides and acid anhydrides (Video)
Nomenclature and properties of esters (Video)
Nomenclature and properties of amides (Video)
Reactivity of carboxylic acid derivatives (Video)
Nucleophilic acyl substitution (Video)
Acid-catalyzed ester hydrolysis (Video)
Acid and base-catalyzed hydrolysis of amides (Video)
Beta-lactam antibiotics
Formation of enolate anions
In this tutorial, Sal and Jay show you how to form enolate anions from aldehydes and ketones.
Keto-enol tautomerization (by Sal) (Video)
Keto-enol tautomerization (by Jay) (Video)
Enolate formation from aldehydes (Video)
Enolate formation from ketones (Video)
Kinetic and thermodynamic enolates (Video)
Aldol condensations
In this tutorial, Sal and Jay show you the mechanism of the aldol condensation and how to predict the products of aldol reactions.
Aldol reaction (Video)
Aldol condensation (Video)
Mixed (crossed) aldol condensation (Video)
Mixed (crossed) aldol condensation using a lithium enolate (Video)
Retro-aldol and retrosynthesis (Video)
Intramolecular aldol condensation
Naming amines
In this tutorial, Sal shows how to name amines.
Amine naming introduction (Video)
Amine naming 2
Infrared Spectroscopy
In this tutorial, Jay introduces the theory of IR spectroscopy and shows how to analyze simple IR spectra.
Introduction to infrared spectroscopy (Video)
Bonds as springs (Video)
Signal characteristics – wavenumber (Video)
IR spectra for hydrocarbons (Video)
Signal characteristics – intensity (Video)
Signal characteristics – shape (Video)
Symmetric and asymmetric stretching (Video)
IR signals for carbonyl compounds (Video)
IR spectra practice (Video)
UV/Vis Spectroscopy
In this tutorial, Jay introduces UV/Vis spectroscopy and color in organic compounds.
UV-Vis spectroscopy (Video)
Absorption in the visible region (Video)
Conjugation and color (Video)
proton NMR
In this tutorial, Jay introduces the theory of proton NMR and shows how to analyze NMR spectra.
Introduction to proton NMR (Video)
Nuclear shielding (Video)
Chemical equivalence (Video)
Chemical shift (Video)
Electronegativity and chemical shift (Video)
Diamagnetic anisotropy (Video)
Integration (Video)
Spin-spin splitting (coupling) (Video)
Multiplicity: n + 1 rule (Video)
Coupling constant (Video)
Complex splitting (Video)
Hydrogen deficiency index (Video)
Proton NMR practice 1 (Video)
Proton NMR practice 2 (Video)
Proton NMR practice 3

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