Material & Energy Balances / Thermodynamics
An intuitive, interactive Material & Energy Balances and Thermodynamics course covering the topics typical of the first two years of a chemical engineering degree. Every lesson pairs plain-language explanations with precise process diagrams, worked examples, hands-on simulations, and practice you can check yourself.
Unlock the full course →
Process Variables & Units
Dimensional analysis, process flow diagrams, and the composition variables every balance relies on.
- Units & Dimensional Analysis 14 min · soon
- Process Flow Diagrams & Composition Variables 16 min · soon
- Mixture Average Molecular Weight & Basis Conversion 14 min · soon
- Density & Specific Gravity 12 min · soon
- Flow Rates & Converting Between Mass and Molar Basis 14 min · soon
Material Balances I: Single-Unit & Unsteady-State
The general balance equation, degree-of-freedom analysis, and the transient case every batch process needs.
- The General Balance Equation 14 min · soon
- Degree-of-Freedom Analysis 16 min · soon
- Single-Unit Steady-State Balances 16 min · soon
- Balances on Multiple Single-Unit Processes 16 min · soon
- Unsteady-State Material Balances 16 min · soon
Material Balances with Reaction
Stoichiometry, extent of reaction, and the conversion/selectivity/yield metrics used throughout reactor design.
- Stoichiometry: Limiting & Excess Reactant 14 min · soon
- Extent of Reaction 16 min · soon
- Conversion, Selectivity & Yield 16 min · soon
- Material Balances on a Single Reaction 16 min · soon
- Material Balances on Multiple Reactions 18 min · soon
Recycle, Bypass & Purge
Multi-unit flowsheets, recycle streams, and the purge calculations that keep inerts from building up.
- Multi-Unit Flowsheets 14 min · soon
- Recycle Streams 16 min · soon
- Bypass Streams 14 min · soon
- Purge Streams & Inert Buildup 16 min · soon
- Degree-of-Freedom Analysis for Multi-Unit Systems 16 min · soon
Energy Balances
The first law, enthalpy and reference states, and energy balances on non-reactive processes.
- Forms of Energy & the First Law 14 min · soon
- Enthalpy & Reference States 16 min · soon
- Heat Capacity & Sensible Heat 16 min · soon
- Energy Balances on Closed Systems 16 min · soon
- Energy Balances on Open (Flow) Systems 18 min · soon
Energy Balances with Phase Change & Reaction
Latent heat, heat of reaction, and adiabatic flame temperature — the flagship module of the balances half.
- Latent Heat & Phase-Change Energy Balances 16 min · soon
- Heat of Reaction & Hess's Law 18 min · soon
- Heat of Combustion 16 min · soon
- Adiabatic Flame & Reaction Temperature 18 min · soon
- Heats of Solution & MixingOptional 14 min · soon
PVT Behavior & Equations of State
Ideal-gas limits, compressibility, and cubic equations of state for real-gas behavior.
- The Ideal Gas Law & Its Limits 14 min · soon
- The Compressibility Factor Z 16 min · soon
- The van der Waals Equation 16 min · soon
- Peng-Robinson & Generalized Correlations 16 min · soon
- PVT Applications in Process Calculations 16 min · soon
Phase Equilibria: Pure & Multicomponent (VLE)
Vapor pressure, Raoult's law, and bubble/dew-point calculations — the capstone of the balances half.
- Vapor Pressure & the Antoine Equation 14 min · soon
- The Clausius-Clapeyron Equation & P-T Diagrams 16 min · soon
- Raoult's Law & Relative Volatility 16 min · soon
- Bubble Point & Dew Point Calculations 18 min · soon
- Henry's Law for Dilute Solutes 14 min · soon
- Humidity & Psychrometric Calculations 16 min · soon
The Second Law & Entropy
Reversibility, entropy balances, and why the second law matters for real process equipment.
- Reversibility & the Second Law 14 min · soon
- Entropy Balances 16 min · soon
- Ideal-Gas Entropy Changes 16 min · soon
- Entropy Generation in Real Processes 16 min · soon
- Second-Law Applications to Process Equipment 16 min · soon
Chemical Reaction Equilibrium
The equilibrium constant, Le Chatelier's principle, and equilibrium conversion — telling equilibrium-limited apart from kinetically-limited.
- Gibbs Free Energy & the Equilibrium Criterion 16 min · soon
- The Equilibrium Constant & ΔG° 16 min · soon
- The van't Hoff Equation & Le Chatelier's Principle 16 min · soon
- Equilibrium Conversion Calculations 18 min · soon
- Equilibrium-Limited vs Kinetically-Limited Reactors 14 min · soon
Capstone: Coupled Mass-Energy-Balance Process Simulation
A multi-unit flowsheet solved end-to-end with combined material and energy balances, plus a VLE flash step.
- Setting Up the Capstone Flowsheet 16 min · soon
- Degree-of-Freedom Analysis for the Capstone 16 min · soon
- Solving the Combined Mass & Energy Balances 20 min · soon
- Recycle Convergence by Iteration 18 min · soon
- Integrating a VLE Flash StepOptional 18 min · soon
New lessons are added continuously. Prefer to test yourself? Try the Chemical Aptitude test.