Stoichiometry & the mole
How to Approach Stoichiometry
The mole-ratio road map that turns any reaction problem into four steps.
Balancing Chemical Equations
A reliable method: one element at a time, oxygen and hydrogen last.
Limiting Reagents Explained
Find the reactant that runs out first and the theoretical yield.
Empirical vs Molecular Formula
The difference, and how to find each from composition data.
Solutions, acids & thermo
Understanding pH and pOH
The pH scale, [H⁺] and [OH⁻], and the pH + pOH = 14 rule.
Strong vs Weak Acids & Bases
Full dissociation versus equilibrium — and which ones to memorise.
Hess's Law & Enthalpy
Add reactions to find ΔH, and use enthalpies of formation.
Gases & reference
The Ideal Gas Law Explained
PV = nRT, choosing the right R, and keeping units consistent.
Significant Figures
The rules that actually matter, and how to round in calculations.
Coming soon
More guides are being written, including: The Henderson–Hasselbalch Equation · What is Ksp? · How to Use ICE Tables · Reaction Order and Half-Life · The Nernst Equation.