General Chemistry
Both semesters of general chemistry, from atoms and measurement through equilibrium, thermodynamics, and nuclear and coordination chemistry.
21 units · 193 topics · 912 questions
How chemists sort the physical world into elements, compounds, and mixtures, and the measurement habits that keep every number honest.
1.2 Classifying Matter: Elements, Compounds, and Mixtures · 1.3 Physical and Chemical Changes · 1.5 Precision, Accuracy, and Measurement Uncertainty · 1.4 SI Units and Dimensional Analysis · +3 more
How the atomic model was pieced together from clues nobody could see directly, and the rules for naming what atoms build once they combine.
2.1 Dalton's Atomic Theory and Its Limits · 2.2 Discovering the Electron: Cathode Rays and the Charge-to-Mass Ratio · 2.2 Rutherford's Gold Foil Experiment and the Nuclear Atom · 2.3 Atomic Structure: Protons, Neutrons, and Isotopes · +7 more
How a chemist bridges the gap between a mass on a balance and a count of particles too small to see, and how that same bridge works for dissolved solutions.
3.1 The Mole and Avogadro's Number · 3.1 Molar Mass and Formula Mass · 3.2 Percent Composition from a Chemical Formula · 3.2 Determining an Empirical Formula from Percent Composition · +5 more
How a balanced equation becomes a recipe you can scale, and what actually happens, ion by ion, when two solutions meet.
4.1 Balancing Chemical Equations · 4.2 Reaction Types: Combination, Decomposition, and Displacement · 4.2 Combustion Reactions of Hydrocarbons · 4.3 Mole-to-Mole Stoichiometry from a Balanced Equation · +8 more
How chemists put a number on the energy a reaction releases or absorbs, and why that number doesn't care which path the reaction took to get there.
5.1 Energy, Heat, and Work · 5.1 Specific Heat and Calorimetry Basics · 5.2 Constant-Pressure Calorimetry with a Coffee Cup · 5.2 Bomb Calorimetry at Constant Volume · +3 more
From a glowing filament's spectrum to the Schrodinger equation's probability clouds, and how the resulting shell structure writes the entire periodic table.
6.1 Electromagnetic Radiation and the Wave Model of Light · 6.1 Quantization of Energy and Planck's Hypothesis · 6.1 The Photoelectric Effect · 6.2 Atomic Line Spectra and the Bohr Model · +9 more
How atoms hold together, from an electron changing owners entirely to two atoms sharing a pair unevenly, and how repulsion alone builds a molecule's shape.
7.1 Ionic Bonding and Lattice Energy · 7.1 The Born-Haber Cycle · 7.1 Covalent Bonding and Electronegativity · 7.2 Drawing Lewis Structures · +6 more
Orbitals actually merging into hybrids, and a molecular orbital diagram that gets oxygen's magnetism right where Lewis structures fail.
8.1 Valence Bond Theory and Orbital Overlap · 8.2 sp3 Hybridization · 8.2 sp2 Hybridization and Pi Bonds · 8.3 sp Hybridization and Triple Bonds · +3 more
Why a gas has no shape of its own, and how far you can push that idea before real molecules stop cooperating with the ideal gas law.
9.1 Gas Pressure and Its Units · 9.2 Boyle's Law: Pressure and Volume · 9.2 Charles's Law: Volume and Temperature · 9.2 The Combined Gas Law and Gay-Lussac's Law · +7 more
The forces between whole molecules, not within them, and how those forces decide whether a substance flows, holds a fixed shape, or conducts electricity.
10.1 London Dispersion Forces · 10.1 Dipole-Dipole Forces · 10.1 Hydrogen Bonding · 10.1 Ranking Intermolecular Forces and Boiling Point Trends · +6 more
How a dissolved solute quietly changes a solvent's vapor pressure, boiling point, freezing point, and osmotic pull, no matter what the solute actually is.
11.1 The Solution Process and Like Dissolves Like · 11.1 Enthalpy of Solution · 11.2 Henry's Law and Gas Solubility · 11.3 Raoult's Law and Vapor Pressure Lowering · +5 more
How fast a reaction runs, why that speed can't be guessed from the equation, and what a catalyst actually changes and what it leaves alone.
12.1 Reaction Rates and How They're Measured · 12.2 Rate Laws and Reaction Order · 12.2 Determining Rate Laws from Experimental Data · 12.3 The Integrated Rate Law for a Zero Order Reaction · +7 more
Why a finished-looking reaction is actually still running both ways at once, and how a pushed system settles into a new balance without undoing the push.
13.1 Dynamic Equilibrium · 13.2 The Equilibrium Constant K · 13.2 The Reaction Quotient Q versus K · 13.4 ICE Tables and Equilibrium Calculations · +2 more
How a proton changing hands defines an acid and a base, and why a solution's pH depends on far more than just how concentrated the acid is.
14.1 Bronsted-Lowry Acids and Bases · 14.1 Conjugate Acid-Base Pairs · 14.2 The Autoionization of Water and Kw · 14.2 The pH and pOH Scales · +8 more
How a solution can be built to resist pH change, how a titration curve reveals it happening, and what equilibrium says about a solid that won't dissolve.
15.1 Buffers: How They Resist pH Change · 15.1 The Henderson-Hasselbalch Equation · 15.1 Buffer Capacity · 15.2 Titration Curves: Strong Acid with Strong Base · +6 more
Why some reactions run themselves and others never will, told through counting arrangements and one equation weighing energy against disorder.
16.2 Spontaneity and the Second Law of Thermodynamics · 16.1 Entropy and Counting Microstates · 16.2 Predicting the Sign of Entropy Change · 16.2 The Third Law of Thermodynamics · +4 more
How separating an oxidation from its reduction forces electrons through a wire instead of straight across, and what running that trick backward buys you.
17.1 Balancing Redox Reactions by the Half-Reaction Method · 17.2 Galvanic Cells and Cell Notation · 17.2 Standard Reduction Potentials · 17.2 Cell Potential and Spontaneity · +5 more
What the periodic table's broad regions actually look like in action, from a metal violent enough to be stored underwater to one element wearing two disguises.
18.1 Periodic Trends in Metallic Character · 18.2 Group 1: Alkali Metal Reactivity · 18.7 Group 17: Halogen Reactivity Trends · 18.3 Allotropes of Carbon · +1 more
Why a transition metal turns a vivid color the instant ligands surround it, and how splitting five equal d orbitals explains the color and the magnetism.
19.2 Transition Metal Complexes: Ligands and Coordination Number · 19.2 Naming Coordination Compounds · 19.2 Isomerism in Coordination Compounds · 19.3 Crystal Field Theory and d-Orbital Splitting · +3 more
How carbon's four bonds build everything from gasoline to a protein, and how a handful of repeating functional groups run all of it.
20.1 Alkanes and Hydrocarbon Nomenclature · 20.1 Structural Isomers · 20.1 Alkenes, Alkynes, and Degree of Unsaturation · 20.2 Alcohols and Ethers · +4 more
Why some nuclei hold together forever and others fly apart on a schedule you can set a clock by, and what happens when one nucleus splits or two combine.
21.1 Nuclear Stability and the Band of Stability · 21.1 Binding Energy and Mass Defect · 21.2 Nuclear Equations and Conservation Rules · 21.3 Types of Radioactive Decay: Alpha, Beta, and Gamma · +7 more