5.1 Reaction Rates

Rate is the change in concentration per unit time. Rates depend on concentration, temperature, surface area, and catalysts.

Rates of different species relate through coefficients: in 2A → B, A disappears twice as fast as B appears.

Rate = −(1/a)Δ[A]/Δt = (1/b)Δ[B]/Δt.

Worked example: N₂ + 3H₂ → 2NH₃. If H₂ is used at 0.30 M/s, NH₃ forms at 0.20 M/s.