Part of PC-08 — Chemical Kinetics

Chemical Kinetics — Key Formulas & Data

by Notetube Officialkey_points summary400 words4 views

Rate of Reaction

rate=1ad[A]dt=1bd[B]dt=+1cd[C]dt=+1dd[D]dt\text{rate} = -\frac{1}{a}\frac{d[A]}{dt} = -\frac{1}{b}\frac{d[B]}{dt} = +\frac{1}{c}\frac{d[C]}{dt} = +\frac{1}{d}\frac{d[D]}{dt}

Rate Law

rate=k[A]m[B]noverall order=m+n\text{rate} = k[A]^m[B]^n \qquad \text{overall order} = m + n

Units of Rate Constant

[k]=(molL)1ns1[k] = \left(\frac{mol}{L}\right)^{1-n} \cdot s^{-1}

Order nnUnits of kk
0molL1s1mol\,L^{-1}\,s^{-1}
1s1s^{-1}
2Lmol1s1L\,mol^{-1}\,s^{-1}
nn(molL1)1ns1(mol\,L^{-1})^{1-n}\,s^{-1}

Integrated Rate Laws

OrderIntegrated LawLinear Plot
0[A]=[A]0kt[A] = [A]_0 - kt[A][A] vs tt; slope =k= -k
1ln[A]=ln[A]0kt\ln[A] = \ln[A]_0 - ktln[A]\ln[A] vs tt; slope =k= -k
21[A]=1[A]0+kt\dfrac{1}{[A]} = \dfrac{1}{[A]_0} + kt1/[A]1/[A] vs tt; slope =+k= +k

Half-Life Formulas

t1/2(0)=[A]02k,t1/2(1)=0.693k=ln2k,t1/2(2)=1k[A]0t_{1/2}^{(0)} = \frac{[A]_0}{2k}, \qquad t_{1/2}^{(1)} = \frac{0.693}{k} = \frac{\ln 2}{k}, \qquad t_{1/2}^{(2)} = \frac{1}{k[A]_0}

Arrhenius Equation

k=AeEa/RTk = A\,e^{-E_a/RT}

lnk=lnAEaRT,logk=logAEa2.303RT\ln k = \ln A - \frac{E_a}{RT}, \qquad \log k = \log A - \frac{E_a}{2.303RT}

Slope of lnk\ln k vs 1/T1/T: slope=EaR\text{slope} = -\dfrac{E_a}{R}

Two-temperature form:

logk2k1=Ea2.303R ⁣(1T11T2),T1<T2\log\frac{k_2}{k_1} = \frac{E_a}{2.303R}\!\left(\frac{1}{T_1} - \frac{1}{T_2}\right), \qquad T_1 < T_2

Activation Energy Relationship

Ea(forward)Ea(backward)=ΔHE_a(\text{forward}) - E_a(\text{backward}) = \Delta H

First-Order Half-Life Chain

[A]t=[A]0(12)nafter n half-lives[A]_t = [A]_0\left(\frac{1}{2}\right)^n \quad \text{after } n \text{ half-lives}

nn[A]/[A]0[A]/[A]_0% Completion
10.50050.0%
20.25075.0%
30.12587.5%
40.062593.75%
100.00097799.9%

Physical Constants

R=8.314Jmol1K1=1.987calmol1K1R = 8.314\,J\,mol^{-1}\,K^{-1} = 1.987\,cal\,mol^{-1}\,K^{-1}

ln2=0.693,log2=0.301,log4=0.602\ln 2 = 0.693, \qquad \log 2 = 0.301, \qquad \log 4 = 0.602

Want to generate AI summaries of your own documents? NoteTube turns PDFs, videos, and articles into study-ready summaries.

Sign up free to create your own