Articles & Guides

The concentration argument that decides reactor choice — the three design equations, the Levenspiel plot, and a worked sizing example where a CSTR needs 5× the volume of a PFR.

Why conversion is the number that lies to you once side reactions show up — the series-reaction trap, a max-yield worked example, and how reactor choice sets selectivity.

Order is measured, not read off the stoichiometry. Molecularity vs order, integrated rate laws, the half-life fingerprint, and finding reaction order from real data.

Activation energy, exponential temperature sensitivity, the Arrhenius plot, where the “doubles every 10°” rule actually comes from, and why cranking the heat can wreck your selectivity.

Why a constitutive law gives you a first derivative, why conservation gives you a second — and how to rebuild the governing equations from scratch instead of memorizing them.

Pr, Sc, Nu, Sh, and the heat/mass circuit analogy — once you see the pattern, half of mass transfer is just heat transfer wearing different letters.

Momentum is a vector, heat transfer gets radiation, and mass transfer's driving force isn't really concentration. The exam-trap conceptual questions live here.

The boiling egg, the igloo energy balance, and perfume diffusing through a stagnant film — the same three-step decision process, every time.

The three boundary layers, why h decays in the laminar region and spikes at transition, and how Pr and Sc control their relative thickness.

Hydrodynamic and thermal entry lengths, bulk mean temperature, the Dittus-Boelter equation, and the two boundary condition cases that give completely different Tₓ(x) profiles.