Chemical Kinetics Cheatsheet

Cheat Codes & Shortcuts

• Definition: Study of the rates of chemical reactions and the factors affecting them.
• Rate Law: \( \text{Rate} = k [A]^m [B]^n \)
• Order of Reaction: Sum of the exponents in the rate law (m + n).
• Zero-Order: Rate = k, independent of concentration.
• First-Order: Rate = k[A], exponential decay.
• Second-Order: Rate = k[A]^2 or k[A][B].
• Integrated Rate Law: Relates concentration to time.
• Half-Life: Time for concentration to halve.
• Arrhenius Equation: \( k = A e^{-E_a / RT} \)
• Activation Energy: \( E_a \), energy barrier for reaction.

Quick Reference Table

Order	Rate Law	Integrated Rate Law
Zero	\( \text{Rate} = k \)	\( [A] = [A]_0 - kt \)
First	\( \text{Rate} = k[A] \)	\( \ln[A] = \ln[A]_0 - kt \)
Second	\( \text{Rate} = k[A]^2 \)	\( \frac{1}{[A]} = \frac{1}{[A]_0} + kt \)
Half-Life (Zero)	\( t_{1/2} = \frac{[A]_0}{2k} \)	Depends on initial concentration
Half-Life (First)	\( t_{1/2} = \frac{0.693}{k} \)	Independent of [A]_0
Arrhenius	\( k = A e^{-E_a / RT} \)	Plot \ln k vs 1/T for E_a

Advice

Chemical Kinetics Quick Tips

• Zero-Order: Rate constant, units M/s, half-life depends on [A]_0.
• First-Order: Rate = k[A], units /s, half-life constant.
• Second-Order: Rate = k[A]^2, units /M s, half-life inversely proportional to [A]_0.
• Arrhenius Plot: ln k vs 1/T gives slope = -E_a/R.
• Catalyst: Lowers E_a, increases rate without being consumed.

Chemical Kinetics Speed Quiz

Test your speed with 5 chemical kinetics questions! You have 30 seconds per question.