3.6 Summary of Reaction Profiles

Reaction Order Rate Law Integrated Rate Law Half-life k

$$\mathrm{A \rightarrow P}$$

Zeroth

$$\mathrm{rate} = k$$

$$\mathrm{[A]}_t = -kt + \mathrm{[A]_0}$$

$$t_{½} = \dfrac{[\mathrm{A}]_0}{2k}$$

M s–1

$$\mathrm{A \rightarrow P}$$

First

$$\mathrm{rate} = k[\mathrm{A}]$$

$$\ln[\mathrm{A}]_{t} = -kt + \ln[\mathrm{A}]_0$$

$$t_{½} = \dfrac{\ln 2}{k} \approx \dfrac{0.693}{k}$$

s–1

$$\mathrm{A + A \rightarrow P}$$

Second

$$\mathrm{rate} = k[\mathrm{A}]^2$$

$$\dfrac{1}{[\mathrm{A}]_t} = kt + \dfrac{1}{[\mathrm{A}]_0}$$

$$t_{½} = \dfrac{1}{k[\mathrm{A}]_0}$$

M–1 s–1

$$\mathrm{A + B \rightarrow P}$$

Second

$$\mathrm{rate} = k[\mathrm{A}][\mathrm{B}]$$

$$\dfrac{1}{[\mathrm{B}]_0 - [\mathrm{A}]_0}\ln\dfrac{[\mathrm{B}][\mathrm{A}]_0}{[\mathrm{A}][\mathrm{B}]_0} = kt$$

$$\cdots$$

M–1 s–1