Last Link-check: 2018.12.22
Note: links shown in {braces} are archived copies of pages that have disappeared and are no longer maintained.
Free downloadable Chemistry textbooks
An Introduction to Chemistry by Mark Bishop. There are two versions of this current textbook, both containing the same information but organized differently: the "Chemistry-first" version begins with actual "chemistry" — that is, chemical equations and reactions. The alternative "Atoms-first" format saves this stuff for later, and begins with atomic theory and bonding. To download PDF versions, select Chemistry-First or Atoms-First. Please note that although you may download these for free, Mark asks that those who make regular use of them pay a shareware fee of $20. Individual chapters for iPad, iPhone, Android devices and Kindle are also available: Chemistry-First, Atoms-First.
Chemical Principles, 3rd Ed (Richard Dickerson, Harry Gray and Gilbert Haight, 1979) - This 1979 text is well-regarded and still good for most first-year General Chemistry courses. Each chapter can be downloaded as a separate pdf file; to see which one you need, move your mouse over the image and the title will appear.
Chemical Principles (CK-12 foundation; Sharon Bewick, Johathan Edge, Therese Forsythe, Richard Parsons) A single 900-page, 51Mb pdf file; download.
General Chemistry - a free textbook compiled from the work of various authors. It is available in the format of a "help" file that works with MS Windows. Please see here for details.
Principles of General Chemistry - available as a PDF file (147 Mb) or as a zip file for use offline with a Web browser.
Thermodynamics and Chemistry - by Howard DeVoe, U. Maryland (2014) This free book in PDF format is a revised and enlarged version of the first edition published in hard-cover format in 2001 by Prentice Hall.
Free Organic Chemistry textbook - Individual chapters of Organic Chemistry by Daley & Daley can be downloaded as pdf files.
College-level online lectures
UC-Berkeley eChem1a: Online General chemistry - These professionally-made videos, most of which feature Prof. Mark Kubinec, are of outstanding quality - perhaps the best college-level general chemistry tutorials available.. There are more than 400 of them, organized into 38 lessons; many of the latter contain problem-solving tutorials, interactive quizzes, and lab demonstrations. Most of the videos are fairly short (5-15 min) and can be accessed in any order.
MIT Principles of Chemical Science - This MIT OpenCourseWare course provides an introduction to the chemistry of biological, inorganic, and organic molecules. The emphasis is on basic principles of atomic and molecular electronic structure, thermodynamics, acid-base and redox equilibria, chemical kinetics, and catalysis. More MIT Chemistry lectures and videos.
Yale Freshman Organic Chemistry - Another excellent series, this one covers the two-semester first-year course which includes organic chemistry. These are llive classroom lectures, given by Prof. J. Michael McBride. His descriptions of the historical development of important concepts is unusually good, and adds to their understanding. Some of the projected slides are hard to read.
First-semester lectures - Second-semester lectures
Reacciones Químicas y Cálculos Estequiométricos - Aprenderás los conceptos básicos de las reacciones químicas y profundizarás en su estudio cuantitativo (estequiometría). (Universitat Politècnica de Valencia)
Web-based resources for General Chemistry
ChemWiki: The Dynamic Chemistry E-Textbook - a collaborative approach toward chemistry education where an Open Access textbook environment is constantly being written and re-written by students and faculty members resulting in a free Chemistry textbook to supplant conventional paper-based books. The material is organized into sections for analytical, biological, inorganic, organic, physical and theoretical chemistry. Each of these contains topics ordinarily included in "general" chemistry, as well as more advanced ones that go beyond first-year college level.
General Chemistry Online! - an interactive guide and Web resource for students and teachers of introductory college chemistry, maintained by Fred Senese of Frostberg State University (MD). A well-organized wealth of material, including collections of notes and guides for introductory General Chemistry, skills checklists and online self-grading examinations, and a Q&A column.
An Introduction to Chemistry - an online version of a text by Mark Bishop of Monterey Peninsula College (CA). It is intended primarily for students in beginning chemistry courses. ($20 "donate-ware", and well worth it!)
Virtual Chembook - this nicely-done site by Charles Ophardt of Elmhurst College covers a wide swath of general, organic, and environmental chemistry. The text material is interesting and well written without attempting to be encyclopedic.
General Chemistry Virtual Textbook - a free collection of comprehensive, in-depth treatments of various topics, intended to supplement or replace conventional textbook treatments. It is aimed mainly at the first-year college level, but advanced high school students will find much of it useful. (Steve Lower, Simon Fraser University)
The Chemogenesis Webbook - this extensive, excellent and comprehensive site by Mark Leach tells how chemistry emerges from the Periodic Table and bifurcates into the rich and extraordinary science that we know and experience.
Chemistry tutorial series on YouTube and other video collections - a summary of the major collections, including the Khan Academy, and those done by various teachers, mostly at the high school level.
WikiBooks on Chemistry - Many topics in general chemistry are covered here, and are worth looking at. But as in any "wiki-" type project to which anyone can contribute, the quality is variable, and the visual design is primitive.
Tanner's General Chemistry - a large collection of pages on matter (including quantum theory), physical chmistry, electrochemistry, and aqueous solutions.
AUS-e-TUTE -an Australian "science education site being developed by experienced teachers." They offer tutorials, texts, games, drills to registered members, as well as an extensive collection of tutorials for non-members.
Chemistry Web Resources - this site maintained by Ron Rinehart of Monterey Peninsula College contains a wealth of material oriented toward chemical education, all well organized in a visually-attractive way.
ChemPaths: Student Resources for General Chemistry - a comprehensive collection of tutorials from the Chemical Education Digital Library
KnowledgeDoor - an excellent compendium of Chemistry- and Science-related data, in many ways more comprehensive than the Handbook of Chemistry and Physics, and certainly more convenient to use. Should be bookmarked by every serious Chemistry student!
The ChemCollective student page has links to practice problems and tutorials on various topics.
College physics for students of biology and chemistry - This hypertextbook by Ken Koehler is nicely organized and is the ideal place to go when your Chemistry textbook lets you down.
How to pass chemistry - sound advice that is widely ignored.
{High School Resources on the Web} - this extensive collection of links at Bob Jacob's Wilton HS site apparently disappeared in early 2008, but this link to a 2007 archived version should still be useful for both high school and college-level General Chemistry.
This Week in the History of Chemistry - part of Carmen Giunta's (Le Moyne College) excellent Classic Chemistry site, "This Week" presents mini-timlines covering the current two-week period.
{Discovery and naming of the chemical elements} - this site by David Trapp organizes the elements according to whether their names are derived from celestial objects, places, minerals, etc.
Discovery of the elements - {Elementistory} provides very brief summaries; the {Los Alamos periodic table} offers more comprehensive historical information.
"Story Problems" - some practical advice for those addicted to "plug-and-chug".
Chemistry Problems - worked examples - This About.com site has a fair selection.
Eight Tips for Success in Science Courses - solid advice from a Georgetown University prof.
Chemistry Packets by veteran teacher Mark Rosengarten. A collection of notes and worksheets in pdf format in two 13-unit sets, one for honors, and the other for Regents Chemistry. Each unit begins with a nicely-organized set of definitions and notes, and contines with worksheets that can serve as student homework. Although directed at the high school, these materials can serve as a good review for college chemistry students.
Purdue University General Chemistry Topics - Notes and practice problems on a large number of topics.
ChemSpider "is a free chemical structure database providing fast text and structure search access to over 58 million structures from hundreds of data sources."
Videos for General Chemistry
There are now problably thousands of these on YouTube and other sites — far too many for one person to review, let alone to keep up to date. In 2013, I created a list of some of the better videos that I considered worth recommnding to others.
Doc Brown's Chemistry Clinic- general review/revision site for UK GCSE, AS and A2 chemistry and USA/Canada grades 9-12. Revision notes, multiple choice tests, structured questions, graphics and extensive links to useful and interesting CHEMISTRY sites. One site speciallity is the structure and naming of organic compounds.
ChemistryCoach is a high school course support page of enclyclopedic proportions. Authored by Bob Jacobs of Wilton High School, this well-organized site contains hundreds of links that will be of interest to students at both the high school and first-year college levels.
ChemThink - This new site consists of a series of interactive quiz-based tutorials. There are also some laboratory simulatons. Registration is required, but is free.
ChemTutor covers a variety of topics - aimed mainly at HS and AP Chemistry.
The Chem Team - Tutorials for High School Chemistry in all standard topics for students in high school and Advanced Placement chemistry.
General Chemistry I, General Chemistry II - "A Virtual Textbook" and a reliable set of lecture notes covering a complete college-level course by Michael Blaber of Florida State U. Look in the left-hand frame to see what topics are available.
Merlin's Principles of Alchemy is a chemistry hypertextbook in the form of a large set of HTML files that users download and then view with their Web browsers off-line. It is organized in an interesting way, and is intended to support users having a wide range of backgrounds and capabilities, including home-schoolers and adult learners. There is a nominal charge for downloading the material.
{Science Help Online Chemistry Lessons} - a nice set of lessons and reference materials by Greg Curran of Fordham Preparatory School.
Quantum theory and the atom - a well-organized and understandable set of Web pages covering quantum mechanics and its applications, including such practical ones as cat scans and microwave ovens. Well worth a look!
Virginia Tech's HyperMedia site has some nice General Chemistry tutorial pages.
Virtual Chemistry Experiments - a collection of interative web-based chemistry tutorials. The tutorials employ Physlets and Chemistry Applets to simulate experiments or depict molecular and atomic structure. Topics include equilibria, kinetics, coordination chemistry, and crystal structure. (David Blauch, Davidson College)
The basics
What is Chemistry all about? An introduction to chemical science. This tutorial attempts to present the major concepts that define modern chemistry, without, of course, getting into the gory details! The unit concludes with an illustrated summary of the main currents of modern chemistry. (S. Lower, Simon Fraser U.)
Preliminaries: stuff you should know before delving too far into Chemistry - tutorials covering the following topics: classification and properties of matter, density and buoyancy, energy, heat and temperature, units and dimensions, measurement error, significant figures and rounding off (these last three topics are identical with the first three in the lesson described immediately below.) (S. Lower, Simon Fraser U.)
Matter and measure: all about units, uncertainty, significant figures,and how to deal with experimental error. Thorough coverage of the basic ideas relating to units and dimensions, the SI system, accuracy, precision, and uncertainty in measurements, significant figures and rounding off, treatment of random and systematic error, standard deviation. (S. Lower, Simon Fraser U.)
Units and conversion factors - see below
LeChatelier's Principle interactive quiz by Gary Bertrand
ChemBalancer and Element Quiz - four games you can play online.
Balancing Chemical Equations - 1270 reactions, organized into easy, intermediate, and "challenging".
Introduction to basic atomics, mole concept, calculations based on formulas and equations, and nomenclature - (S.K. Lower, SFU) these five lessons offer in-depth treatment of these topics at an introductory level.
Acids and bases
All about acids and bases - this set of seven lessons covers everything you need to know about the fundamental concepts (Arrhenius, Brønsted-Lowry, and Lewis) of acids and bases. Other lessons cover an elementary treatment of pH and titration, how to recognize acidic and basic substances from their structures, and a gallery of commonly-encountered acids and bases. Aside from the material on pH, there is no math in this lesson set; acid-base equilibrium calculations are not covered here.
Acid-base without algebra A simple graphical method of solving pH problems that gives as good answers as algebraic solutions and provides a global view of what species are significant at any pH. Especially useful for polyprotic systems which would otherwise require solution of many simultaneous equations.
Acid-base tutorial (PDF format; Dan Dill, Boston U) - this excellent tutorial covers all the major topics commonly encountered at the general chemistry level, with an unusualy thorough treatment of buffer systems.
ChemBuddy pH Calculation tutorials - an extensive set of online tutorials covering most aspects of acid-base calculations. A good collection of titration- and other plots.
Acid and Base Tutorial (U of British Columbia) - Another nicely-organized set of lessons, each consisting of a well-done tutorial, plus a multiple-choice quiz.
The fall of the proton: Will this acid react with that base? How to understand acid-base reactions (This simple view of modern acid-base theory dates from 1954, but still hasn't made it into the standard textbooks.
Acid-base review (UNC-Chapel Hill) offers a compact treatment of the fundamentals of acid-base calculations.
Acid-base titration simulator - this easy-to-use page allows you to explore a large variety of acid-base systems, including polyprotic ones. There is also the choice of using "first-year" or mass-charge balance methods.
Atomic theory
Atoms and the periodic table - a six-chapter first-year level treatment of basic quantum theory, atomic spectra, electron configurations, chemical periodicity and the organization of the periodic table. Part of S.K. Lower's General Chemistry Virtual Textbook.
Basic atomics: atoms, elements, and isotopes - an introductory treatment for beginning students, suitable for the very early part of a general chemistry course. (SK Lower, Simon Fraser University)
Introduction to the electronic structure of atoms and molecules - a well-organized series of pages which extend into chemical bonding. (Alfred Bader, McMaster U)
Primer on Quantum Theory of the Atom - A set of in-frequently asked questions in the form of a quantum catechism.
Atomic orbital visualization - see the The Orbitron: a gallery of orbitals -- and also the references on our visualization page.
{What is a wave function? What is an orbital?} An Introduction to Quantum Mechanics - a set of 16 modules with text, diagrams, and [optional] spoken descriptions from Ohio State University. (≤ 2008)
Introduction to Atoms - A concise exposition of the principles (including elementary quantum theory) with some interesting twists. John Denker
The Mystery of Matter: Search for the Elements - This PBS video " is an exciting three-part series about one of the great adventures in the history of science: the long and continuing quest to understand what the world is made of. Three hour-long episodes tell the story of seven of history’s most important scientists as they seek to identify, understand and organize the basic building blocks of matter."
Hunting the Elements - A Two0hour PBS/NOVA video. "Where do nature's building blocks, called the elements, come from? They're the hidden ingredients of everything in our world, from the carbon in our bodies to the metals in our smartphones. To unlock their secrets, David Pogue, technology columnist and lively host of NOVA's popular "Making Stuff" series, spins viewers through the world of weird, extreme chemistry: the strongest acids, the deadliest poisons, the universe's most abundant elements, and the rarest of the rare—substances cooked up in atom smashers that flicker into existence for only fractions of a second." Note: this video is not viewable in Canada (and possibly in other countries) owing to stupid "rights" issues.
Chemical Bonding
All about chemical bonding (Steve Lower, SFU) - this 10-part site provides in-depth coverage of everything you need to know about molecular structure and bonding at the General Chemistry level. Includes separate sections on polar covalence, VESPR, hybrid orbitals, molecular orbitals, coordination complexes and metals.
Chemical bonding - the really basic stuff! (S. Lower, Simon Fraser U.)
Models of chemical bonding - Do chemical bonds really exist? Nobody has ever "seen" one, so the best we can do is construct models. Here is a brief summary of those you should know about.
Covalent, ionic, or what? Coming to terms with covalent, ionic, and metallic bonding, and with mixtures thereof. Guaranteed to give you more insight to this than your textbook does!
The electron-tunneling model of chemical bonding How can those electron-dot diagrams showing shared electrons happily sitting between the nuclei be consistent with the principle that opposite charges attract? The model described here is the simplest one that really explains bonding, but you are unlikely to find it in any textbook!
VSEPR theory - This summary with easy access to many images is a hypertext version of the chapter on this subject from a textbook by Mark Winnter (U Sheffield).
VSEPR for General Chemistry - This Purdue University site features a useful set of practice problems and requires the downloadable CHIME plug-in.
Electrochemistry
All about Electrochemistry - An in-depth, comprehensive treatment (Steve Lower)
Electrochemistry: Voltaic & Electrolytic Cells (Ralph Logan)
{Electrochemistry class notes} (1997-2004) by J. Baird of Brown Univ.
Gases
Properties of gases: matter at its simplest - a six-part "virtual textbook" treatment of the gaseous state of matter by Steve Lower. Includes numerous examples of application of kinetic molecular theory and a section on real gases. (Part of the Chem1 Virtual Textbook)
Intermolecular forces
Interactions between molecular units - this tutorial for first-year students looks at ionic-, van der Waals attractions, and the universal repulsive force, and how these lead to potential energy curves. (Part of the Chem1 Virtual Textbook)
Kinetics
Chemical Kinetics and Dynamics - An introduction to rates of reaction, rate laws, half-life, activation energy, the Arrhenius equation, and reaction mechanisms. (Chem1 Virtual Textbook)
Chung Chieh's {Chemical Kinetics tutorial} at U of Waterloo (Canada) includes test questions with answers. (≤ 2010)
Kinetics Explorer - an introduction to the study of chemical kinetics based on the exploration of dynamic phenomena. Includes some good simulations. (St. Olaf College)
Online kinetics simulator from Gary Bertrand.
{Principles of Chemical Dynamics tutorial} (WPI) is college-level with problem examples (≤ 2009)
Moles, formulas and reaction calculations
{Chemical reaction stoichiometry} site provides tutorials for both beginners and advanced students on how to generate a proper set of chemical equations to represent the stoichiometry of a reacting system of any degree of complexity. (< 2010)
The mole concept, calculations based on formulas and equations - these three chapters of the Chem1 Virtual Textbook provide in-depth treatment at an elementary level. (Part of the Chem1 Virtual Textbook)
{Molar Masses}: Atomic, molecular and formula masses or "weights" - a nice tutorial, with built-in quiz, for beginning students. (David Dice)
Balancing Chemical Equations - this ChemTeam site provides numerous links and drills.
Oxidation-Reduction
The fall of the electron. How to predict the direction of oxidation-reduction reactions. Discussion of the activity series of the elements and of oxidation-reduction in metabolism. (S.K. Lower, SFU)
Redox reactions (UNC-Chapel Hill) Good summary of how to balance redox reactions; also covers cell potentials and Faraday's laws.
ChemTeam lessons on oxidation-reduction
Nuclear Chemistry
{Nuclear chemistry tutorial} by Steve Marsden
The Particle Adventure: the fundamentals of matter and force. This Lawrence Berkeley National Laboratory site allows you to explore the world of fundamental particles and forces and then to investigate the experimental evidence and techniques.
Marie Curie and the Radium Craze - (a PBS video) "After Marie and Pierre Curie’s discovery of radium, the new element’s wondrous ability to glow in the dark inspired a worldwide craze — a rush of radium-laced products that promised to cure everything from impotence to hair loss. What few people realized — and the Curies were reluctant to admit — was the great harm this radioactive element could do."
Periodic Tables
For periodic table T-shirts, neckties, etc., see here
{ChemistryCoach's Periodic Table links} - a huge but well-organized list of every possible kind of periodic table you can think of, as well as games, software, etc. (≤ 10/2006)
ChemiCool Periodic Table (MIT)
Visual Key and Quantum Fold periodic table - This enhanced periodic table by Dr. Eric Scerri, author of The Periodic Table: its Story and its Significance, opens up accoriation-wise "to show hidden patterns that can't be seen in textbooks and wall charts." It can be purchased for US$10 from this site.
The Periodic Table of Videos - This is not just another periodic table, but a huge resource that has expanded to include more than 500 videos, mostly quite short. At its simplest, you just click on an element, and watch a two-minute video that describes the element and its uses. There is also a larger series of "Molecular Videos" that describes different chemical substances and their uses — all designed to convey the fascination of Chemistry. Most of these videos star the picturesque Sir Martyn Poliakoff, a professor of Chemistry at the University of Nottingham in the U.K., where this project is based.
Chinese periodic tables - Yes, there are such things! {Here's an impressive one}, and see this Wikipedia article which has some examples.
Comic book periodic table - if both comics and chemistry are important in your life, you'll love this!
The Photographic Periodic Table of the Elements - the home page features photographs of (or related to) the elements, but it includes "many thousands of pages of text, stories, pictures, and data" by Theodore Gray.
It's Elemental - this is not so much a periodic table as a series of links to excellent and interesting articles focussing on the history and uses of each element, written by authors having special expertise or interest in the element. Written in a style more journalistic than scientific, this set of articles appeared in a special 80th anniversary edition of Chemical & Engineering News.
iPod periodic table - well, it's not really the whole table, but just a handy element database to store along with your music.
Periodic Table mnemonic song - 
Periodic Table of Poetry "Chemistry and poetry together as never before."
Elemtymology & Elements Multidict - What do they call the element strontium in Georgia (the country, not the state!)? Answer: სტორცინიუმი. If gems like this fascinate you, have a look at this site, which is all about the origins of the element names, not just in English, but in 97 different languages.
Periodic Table of Haiku - for those who find elements lyrical.
WebElements (Sheffield, UK) The elements in this online periodic table are linked to an extensive variety of chemical and physical data as well as background, crystallographic, nuclear, electronic, biological and geological information. You can ever hear how the Brits prounounce the name of the element!
Significant figures
> Significant figures and rounding off: How to avoid telling lies with numbers. Provides an understandable, in-depth explanation with many examples. Provides an understandable, in-depth explanation with many examples. (S.K. Lower, Chem1 Virtual Textbook)
Solids and materials
Exploring the Nanoworld - This wonderful site is maintained by the NSF-financed Interdisciplinary Education Group at U Wisc-Madison. It uses examples of nanotechnology and advanced materials to explore science and engineering concepts mainly at the college level, but there are also sections for K-12. There are links to movies, lab experiments, kits (including Lego nanobricks) and instructional materials.
Ionic and ion-derived solids - a detailed look at alkali halide energetics and structures, and extended structures. (Part of the Chem1 Virtual Textbook)
Introduction to crystals - how the external forms of crystals relate to their internal structures. Cover the empirical laws of crystals, lattices and unit cells, Miller indices, and factors affecting growth habits. (Part of the Chem1 Virtual Textbook)
Cubic crystal lattices and close packing - the origins of long-range order in solids. Face-centered and body-centered structures. (Part of the Chem1 Virtual Textbook)
Exploring Materials Engineering - links to a variety of sites relating to materials and polymer science.
BuckyBalls (Buckminsterfullerenes, those soccer-ball-like carbon structures). This Nanotechnology Now site has a good overview of nanotubes and Buckyballs and many links.
Polymers. The outstanding site Macrogalleria covers the structures and properties of polymers in an uncommonly engaging way. Highly recommended.
Thermodynamics
Chemical Energetics: all about enthalpy, thermochemistry and the First Law of thermodynamics - An extensive, in-depth but largely non-mathematical substitute for the usual (and rather thin) textbook treatment. S.K. Lower, Simon Fraser University
Thermodynamics of equilibrium: all about entropy, free energy, the Second Law of thermodynamics, and why reactions take place— sometimes. S.K. Lower, Simon Fraser University.
Energy, enthalpy, and the First Law - a nice set of tutorials from Purdue U.
{The Page of EntRopY} - a very understandable exposition of this difficult topic by Dave Slaven of Saginaw Valley State U.
The Second Law: The biggest, most powerful, most general idea in all of science. A lively, non-mathematical exposition of the way that entropy and activation energy battle it out in the world as we know it. By Frank Lambert of Occidental College. An alternative version, directed to non-science students and adults, is also available. See also Lambert's non-technical description of how activation energies modify the application of the Second Law. See also Shakespeare and Thermodynamics: Dam the Second Law, and Entropy is Simple...If We Avoid the Briar Patches!.
The Second Law of Thermodynamics, Evolution, and Probability. Explains how the development and evolution of life is consistent with the principle that the entropy of the world never decreases.
Kelvin is Lord!! All praise Lord Kelvin! A spoof cult site for the thermodynamically inclined.
Units and conversion factors
Units and dimensions for chemistry - includes charts showing the ranges of the scales such as length, mass, temperature, etc. that are important in chemistry.
Online unit conversions - Here are several useful ones: OnlineConversion.com - "digital dutch" Unit Converter - convert-me.com - EasyUnitConverter -Convert Auto -
Units, measures and conversions information can be found at a number of sources:
- Wikipedia's Table of Conversion Factors
- The NIST Guide to the SI is good for those mired in the swamp of U.S. non-SI units
- Canceling Units - a nice tutorial on how to do the math of unit conversions
- This Numericana page has an eclectic collection of units, including some rather uncommon ones.
- For those interested in the arcane: Obsolete and ancient measurement units
101 Qustions and answers - You are bound to find some interesting questions here that you never thought of asking!
How do I solve it? This excellent page from Purdue U. contins links to guides for solving many of the typical quantitative problems encountered in General Chemistry.
Just ask Antoine - If your instructor doesn't have the answer, try here! Conducted by Fred Senese of Frostberg State Univ ersity (MD) as part of "Project Antoine".
Newton: Ask a Scientist - an online community for science, math and computer science teachers and students. NEWTON is operated byArgonne National Laboratory.
AP Chemistry Practice Tests - A large collection of free practice tests covering many topics at the AP level.
The Chemistry Cluster is a Yahoo group where you can ask (or answer!) questions.
Chemical Forums for students of Chemistry - a place where you can post questions and answers. There are separate forums for high school chemistry, college general chemistry, organic, analytical, physical nuclear and inorganic chemistry, and chemical biology, as well as others of more general interest. Registration is required, but it is free.
ChemiCool forums is another site on which you can post questions and answers relting to General Chemisry and biochemistry as well as organic, theoretical and computational chemistry.
Cramster is another board for "chemistry help" with practice exams, textbook excerpts, and user-posted questions.
brainly chemistry - yet another site for chemistry questions and answers
Chemistry tutors for hire - You can use this WyzAnt site to search for local tutors, review profiles and qualifications, run background checks, and arrange for in-home lessons.
Atomic Weights of Ten Chemical Elements About to Change - and you thought that atomic weights were forever? See this December 2010 news release from the US Geological Survey!
Chemistry of Cleaning - a nice overview of the nature of "dirt" and the agents used to get rid of it. Another useful source: the York U. (UK) page How do detergents work?" features some simple experiments on soap bubbles and surface tension. Chemistry behind cleaning contains many useful links to other sites.
Stain removal guide - How to remove just about every kind of stain you can think of.
Science of Cooking - A well-designed site from the Exploratorium science museum in San Francisco. Links to topics from bread to pickles help enhance understanding ot the science behind food and cooking.
{What's in a modern laundry detergent?} Surfactants, builders, flllers, brightening agents to attract consumer dollars. {≤ 2008)
Food Science Videos - good collection of videos
More Food Chemistry sites: Chemistry of Chili Peppers; (The Chemistry of Tea} - Dairy Chemistry and Physics - Fire and spice: the molecular basis of flavor - Table of condiments that periodically go bad - Structure of Ice Cream - How to Make Rock Candy
Freezing point depression FAQ - from "Ask Antoine"
{Decomposition: what happens to the body after death) - This site from the Austrialian Museum describes the natural chemical and biological processes that will eventually happen to all of us. [This site died in 2008; link is to latest archived version]
{The Happy Drinking Bird} - all about the various subspecies of "dippy birds", their history, and how they work. (≤ 7/2007)
The Chemistry of Egg Whites - an unusually well-done treatment of this topic.
How to boil an egg - all about eggs and the science of hard-boiling them by Charles Williams (U Exeter, UK)
Structure of ice cream - all about the chemistry and physics of your favorite treat from the Dairy Science Faculty of the Unversity of Guelph (Ontario, Canada)
Stain removal guide - here is something to make your parents regard you as a Chemistry expert!
> Skunk Spray Chemistry - what's the big stink about? What's in skunk spray, and what can you do about it? This page by W.FD. Wood of Humboldt State U (CA) tells all.
Why Did My Skin Turn Green? How to keep jewelry from discoloring your skin.
Why does eating asparagus make your pee smell funny? - Impress your friends with your understanding of their embarassing secrets! For information on other disgusting bodily fluids and odors, check out the Grossology site.
Why are things colored?
Why is water blue? It's all about O-H bond stretching! The Causes of Color section has pages on Why is water blue? and What causes the blue color that sometimes appears in snow and ice?
Water to Wine: the molecular basis of indicator color change (from the General Chemistry Online site)
{Why do leaves become brightly colored in the autumn?} Who says that science can't help us appreciate the beauties of nature? (≤ 7/2010)
Why is the sky blue? Simplified explanation - More complete explanation describing Rayleigh scattering.
Science Knowledge Quiz - "Test your knowledge of science facts and applications of scientific principles by taking our short 12-question quiz. Then see how you did in comparison with a nationally representative group of 3,278 randomly selected U.S. adults surveyed online and by mail between Aug. 11 and Sept. 3, 2014 as members of the Pew Research Center’s American Trends Panel."
Chemistry Explained: Foundations and applications - At first glance, this site appears to be just an A-Z index to a series of short definitions of the many topics it covers, but clicking on the name of the topic itself brings up a fairly detailed (but anonymously composed) description or exposition of the subject.
> {The A through E approach to Problem Solving in Chemistry} by David Woodcock. A series of handounts in Web page format describing how to approach General Chemistry problems. (The original site is long gone, but this archived advice is still worth knowing!)
The Alchemy Web Site - A very comprehensive source.
> Blogging the Periodic Table - "a series of 28 "Wild, weird, wonderful stories about the elements that make up our universe" by Sam Kean. This series appeared in Slate in mid-2010.
What is chemistry good for? (A nice rejoinder to those who accuse chemistry of polluting the world.)
Elemental discoveries A weekly 'zine featuring chemistry topics and reviews.
Emulsions and cooking - This Science in the kitchen page discusses the role of emulsions in milk, salad dressings, butter and peanut butter.
How Bread Works - You probably eat bread every day. You may even know how to make your own bread. But have you ever thought about bread as atechnology?
Human Thermodynamics - this rather far-out site apparently seeks to relate chemical affinity to human interactions.
The Chemistry of Wood - a 6-minute video from Glasgow University about this ubiquitous substance. 
Measure Converter - conversion factors between SI and cgs units of all kinds, organized both by category and name of unit. OnlineConversion.com is a similar site.
Mineral Gallery - A good minerology site with information and excellent photos of a large number of minerals organized both by name and by classification.
What is pseudoscience? All about pseudoscience, bad science, and pathological science. How to tell the difference from science. If you are interested in science, you ought to know something about the nonsense that is being flogged in the name of science. (S.K. Lower, Simon Fraser University)
Water to wine: The molecular basis of indicator color changes. A very well-done site with interesting graphics and lots of cross-links. Very readable and interesting, set at the "Scientific American" level and suitable for high school and introductory college courses.
Boiling water without bubbles - an interesting article about the nanoparticles and the Leidenfrost effect.
John Oliver on "scientific studies" and their reporting - A Last Week Tonight YouTube video on how and why media outlets so often report untrue or incomplete information as science.
General Chemistry Jeopardy games - a collection from U. Pittsburgh
Chemistry Trivia Quizzes - this site provides access to a variety of quizzes from different sources.
Chemistry humor
{Chemistry Cartoons} - from the archived collection of Mr. Seiler, an Illinois high school teacher.
Chemistry Joke-a-rama - guaranteed by the American Chemical Society to make you laugh.
{Nearing Zero}: an archive of largely satisfactory science cartoons from "Nick"
{Science Jokes} (including over 200 on Chemistry) (≤ 2009)
Molecules with silly or unusual (or suggestive) names - an amusing and informative site by Paul May of Bristol U (UK) that will likely have special appeal to teen males of all ages.
Science humor WebRing - some of it is pretty corny.
{What students say - what professors hear} - this bit of wisdom was found on the Marshall U. (WV) site.
The story of Schroedinger's cat (an epic poem)
The Table of Condiments that Periodically Go Bad — taking the periodic table a bit too far!
"Ban DHMO" (dihydrogen monoxide) page. It can kill you! All about this nefarious chemical in our environment.
{Nightmare acid-base lesson} - one of Mark Wutka's WeirdWorks stories
Sciences Jeopardy! Games - this U Pittsburgh site covers general, organic, analytical and biochemistry.
Organic Chemistry Music Video "Resistant to Base" (YouTube)
Chemistry-related apparel and accessories
Show the world that chemistry matters to you! Here are a few U.S. suppliers of periodic table T-shirts and other great conversation-starters.
Cotton Expressions offers some nice chemistry, biology and geology T-shirts.
SCIENCETeeCHER T-shirts are still available here..
Science On T-Shirts has a wide selection of Chemistry-related slogans, some pretty corny.
Made-with-molecules This scientist-turned artist with a fascination for molecules offers molecule-themed silver jewelry, keychains, baby gifts, holiday cards— and, for the guys, testosterone boxer shorts.
The Atomic Dashboard - is an interactive chemistry resource and learning tool developed for the Mac by Bitwixt Software Systems. Used by educators, students, scientists, and the simply curious. With its 3D Molecule Library, and its 3D models of atomic orbitals, molecules, compounds, gases, and crystals, The Atomic Dashboard helps you explore the relationships between the behavior of atoms and molecules and their 3D structure. Mac App Store, $15.
CurTiPot - Freeware for pH and acid-base equilibrium calculations and for simulation and
analysis of Potentiometric Titration Curves
Intelli Balancer - this downloadable, Windows-only program will balance almost any chemical equation for you.
The Atomic Mac is a shareware periodic table-oriented database including isotopic and nuclear data) on the elements. Also includes a molecular weight calculator.
Atom-in-a-box is a Macintosh shareware application that displays atomic orbitals in real-time.
3D Chemical Elements Screensaver is also an interactive Periodic Table and 3D Atom Modelling program. $20 and for Windows only.
Linux4Chemistry page lists a number of Chemistry applications, including open source, freeware and shareware
Chem1 Concept Builder for General Chemistry - now Free!
This set of lessons that provide guided, interactive instruction in General Chemistry at the college and advanced high school levels.These materials are suitable for home study or as a supplement to a formal course. All lessons start at a very elementary level, and many of them go somewhat beyond the content of the standard first-year course, making them useful to students enrolled in analytical chemistry, biochemistry, and environmental chemistry courses. Windows 3.1 throuhgh XP.
ChemBuddy pH Calculator calculates the pH of any mixture of strong/weak/polyprotic acids and bases, with or without ionic strength or ativity corrections, and can draw titration curves. It also contains an extensive database of acid/base data.
Chemistry structure-drawing software
Symyx Draw is a free Windows-only application that you can use it to draw chemical structures and export them for viewing as 3D models. Symyx Draw is a successor to Isis/Draw which is no longer available.
ACD/ChemSketch is a free-for-noncommercial-use application for Windows or Linux that offers 3D optimization, viewing and rotation, cut and paste into other applications, and tautomer prediction.
> ChemDraw "is the industry standard software used by scientists worldwide to draw accurate, chemically-aware structures for use in database queries, preparation of publication-quality graphics, and entry for modeling and other programs that require an electronic description of molecules and reactions." Versions are available for both Windows and Mac-OS, and a deep discount is available to students.
EasyChem is a free multi-platform GPL program that draws publication-quality structures.file:///Users/slower/Web/ChemEd/genchem.shtml
iMol is a free molecular visualization application for Mac OS X operating systems. iMol supports several file formats. It can easily handle small and large molecules, loads multiple molecules, can move and rotate them independently, or displays a molecular dynamics trajectory.
Sources of free molecular modeling software are listed at the MathMol site -
Free software from the Journal of Chemical Education's JCE Software series is now available. The catch: it is pre-Windows (DOS), but some of it is quite good.
Trinity software offers student discounts on all its products which include a number of titles in General Chemistry.
Utility calculators for Chemistry
Students: you would be wise to avoid depending on these utilities for routine in beginning courses; you really need the practice in working these problems out for yourself!
MoleCalc is a free molecular weight calculator Windows-only utility by Davd Defoort. You type in the formula, and it returns themolecular weight.
Free Molecular weight calculators by Matthew Monroe (Windows only)
Online Molecular Weight Calculator from Lenntech
MW calculators for Macintosh OS X: Digital Science (includes built-in periodic table reference) - Structural
iPhone/iPod MW calculator: Invitrogen Science Calculator - Online formula and molar mass calculator - LabCalPlus for the iPad
Online solution calculators: mass to make up solution of given volume and molarity; dilute a stock solution to given volume and molarity
CurTiPot acid-base software - All-in-one freeware for pH and acid-base equilibrium calculations and for simulation and analysis of Potentiometric Titration Curves.
Model ChemLab is a real-time 2-D simulation of a chemistry lab in which the user interacts with animated lab equipment in a large number of experiment modules (see list.) An inexpensive version is available for about $25. Macintosh and Windows; Free demo available by download.
> MoluCAD is a full-featured molecular modeling and visualization tool designed for personal computing platforms. It was developed with NSF support and is available to students at a very low price. Both Macintosh and Windows versions can be downloaded. The latest version incorporates many advanced features only found in expensive workstation-based modeling packages. Novice users are able to quickly generate models, view them form any perspective, create reaction animations, and save all data to disk.
For Chem junkies only! The Chemical Thesaurus is a huge (200 Mb) collection of information about chemical reactions, phase changes and radiochemistry organized into a relational database. It is free for personal use and available in both Windows and Macintosh versions.
Equation- and function plotting software
See the list that has been compiled byWikipedia
Some Web-based online function plotting utilities are QuiSoft, FooPlot, and Zorn's Online Function Grapher.