How do you experimentally determine activation energy?

Method: measure rate constants at multiple temperatures, then use Arrhenius plot. Plot ln(k) vs 1/T - slope equals -Ea/R. Linear regression gives activation energy from slope. Requirements: kinetically-controlled conditions (no mass transfer limitations), accurate temperature measurement, sufficient temperature range (typically 20-50K span), and verified reaction order. Differential reactor or initial rate method preferred. Compare apparent activation energy: ~40-80 kJ/mol for chemical kinetics, <20 kJ/mol indicates diffusion control, >100 kJ/mol for strong temperature dependence.