General Chemistry I

The route

Lessons are in the order that makes each one easier than the last. Each unit ends with a short quiz.

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   Unit 1

   Matter, Measurement and the Gas Laws

   What matter is, how its particles behave, how to measure it honestly, and how gases respond when you squeeze or heat them.
   1. Matter and Its ClassificationFree Every substance you will ever meet sits somewhere on one simple family tree. 10 min
   3. States of Matter and the Kinetic Theory Same particles, different freedom. Why sweat cools you and why ice keeps its shape. 10 min
   4. SI Units, Scientific Notation and Significant Figures A number without a unit is gossip. A number with too many digits is a lie. 10 min
   5. Unit Conversion (Dimensional Analysis) and Density Multiply by one, cleverly, and any unit turns into any other. 10 min
   6. The Gas Laws: Boyle, Charles and Gay-Lussac Why a tyre that was fine at dawn can be overinflated by afternoon in the harmattan. 10 min
   7. Unit 1 quiz6 questions on this unit 8 min
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   Unit 2 Full plan

   Atomic Structure

   Protons, neutrons and electrons, isotopes and relative atomic mass, the models from Dalton to Bohr, and the four quantum numbers.
   1. Subatomic Particles, Atomic Number and Mass Number Three particles build every atom in the universe, and two numbers tell you how many of each. 10 min
   2. Isotopes and Relative Atomic Mass Same element, different weights. The reason the periodic table is full of decimals. 10 min
   3. Atomic Models: Dalton to Bohr Four scientists, four models, and one shocking bounce off a sheet of gold. 13 min
   4. Quantum Numbers and Atomic Orbitals Every electron in an atom has a four-part address, and no two share the same one. 10 min
   5. Unit 2 quiz7 questions on this unit 9 min
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   Unit 3 Full plan

   Electronic Configuration and the Periodic Table

   Filling orbitals by the Aufbau, Pauli and Hund rules, and reading the periodic table's trends from the electrons outward.
   1. Electronic Configuration: Aufbau, Pauli and Hund Three house rules decide where every electron sits, from hydrogen all the way to iron. 10 min
   2. Electronic Configurations of Atoms and Ions The shorthand that fits a whole atom on one line, plus the two famous elements that break the pattern. 10 min
   3. The Periodic Table: Periods, Groups and Blocks Give it an electron configuration and the table tells you the address, and the address tells you the personality. 10 min
   4. Periodic Trends Atoms shrink across a row and swell down a column. Two forces explain every trend in the table. 14 min
   5. Unit 3 quiz6 questions on this unit 8 min
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   Unit 4 Full plan

   Chemical Bonding and Shapes of Molecules

   Ionic, covalent, dative and metallic bonds, Lewis structures, VSEPR shapes, polarity and the intermolecular forces that hold water and DNA together.
   1. The Octet Rule and Ionic Bonding Sodium gives, chlorine takes, and the salt on your plate holds together by pure attraction. 10 min
   2. Covalent, Dative and Metallic Bonding When neither atom will let go, they share. When there are too many to share, they pool. 12 min
   3. Shapes of Molecules (VSEPR Theory) Electron pairs push each other as far apart as they can, and that one idea predicts every shape. 10 min
   4. Bond Polarity and Intermolecular Forces Why water boils at 100 °C when it 'should' boil far below zero, and how DNA zips and unzips. 14 min
   5. Unit 4 quiz6 questions on this unit 8 min
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   Unit 5 Full plan

   The Mole Concept and Stoichiometry

   Counting particles by weighing, formulas from percentages, balanced equations, reacting masses, limiting reagents, yields and the ideal gas equation.
   1. The Mole Concept Nobody counts grains of rice one by one at the market. Chemists don't count atoms either. They weigh them. 10 min
   2. Percentage Composition, Empirical and Molecular Formulas Give a chemist the percentage of each element and she can tell you the formula. Here is the recipe. 10 min
   3. Balancing Chemical Equations and Reacting Masses A balanced equation is a recipe in moles. Read it right and you can predict any mass before you mix anything. 10 min
   4. Limiting Reagent and Percentage Yield The reactant that runs out first calls the shots, and real reactions never quite deliver what the equation promises. 10 min
   5. The Ideal Gas Equation, Dalton's Law and Graham's Law One equation for any gas, the reason air at Jos feels thinner, and why ammonia wins a race down a glass tube. 10 min
   6. Unit 5 quiz7 questions on this unit 9 min
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   Unit 6 Full plan

   Solutions, Acids, Bases and Buffers

   Concentration and dilution, acid-base theories, pH, titration calculations and the buffer that keeps your blood at pH 7.4.
   1. Concentration of Solutions and Dilution What 0.9% on a drip bag really means, and how to make any weaker solution from a stronger one. 10 min
   2. Acids and Bases: Arrhenius and Brønsted–Lowry Theories Two definitions, one proton, and the acid your stomach makes every time you smell food. 12 min
   3. pH, pOH and the Ionic Product of Water A scale from 0 to 14 that squeezes a hundred-trillion-fold range of acidity into numbers you can say out loud. 10 min
   4. Acid-Base Titration and Buffer Solutions How to find an unknown concentration drop by drop, and how your blood shrugs off acid to stay at pH 7.4. 15 min
   5. Unit 6 quiz8 questions on this unit 10 min

Practise and remember