Rate Law

The Rate Law calculator has rate of reaction functions for Zero Order, First Order and Second Order reactions as follows:

• Zero Order Rate Law (Integral form)
• Zero Order  Half Life
• Zero Order Rate Law
• First Order Rate Law (Integral form)
• First Order Half Life
• First Order Rate Law
• Second Order Rate Law (Integral form)
• Second Order Half Life
• Second Order Rate Law

The Science

Kinetics is a category in chemistry concerned with the rate of the reaction. The rates of reactions are dependent on temperature, concentration of reactants, presence of catalysts and molecular mechanisms by which the reaction occurs. The rate of the reaction is proportional to the concentration of the reactants or products, and depending on the order of the reaction, is raised to the power of that order. On molecular level reactions occur either unimolecularly or bimolecularly, where the structure of the reactant(s) changes due to collisions. In order for the molecular structure change to occur, an amount of energy called activation energy must be given for the reaction to occur.

Chemistry Calculators

• R - Gas Constant: 8.3144626181532 J/(K⋅mol)
• Boyle's Law Calculator:  P₁ • V₁ = P₂ • V₂
• Charles Law Calculator: V₁• T₂ = V₂ • T₁
• Combined Gas Law Calculator:   P•V / T= k
• Gay-Lussac Law:  T₁•P₂ =T₂•P₁ 
• Ideal Gas Law: P•V = n•R•T
• Bragg's Law:   n·λ = 2d·sinθ
• Hess' Law:  ΔH⁰_rxn=ΔH⁰_a+ΔH⁰_b+ΔH⁰_c+ΔH⁰_d
• Internal Energy: ΔU = q + ω 
• Activation Energy:  E_a = (R*T₁⋅T₂)/(T₁ - T₂) ⋅  ln(k₁/k₂)
• Arrhenius Equation:  k = Ae^E_a/(RT)
• Clausius-Clapeyron Equation:  ln(P₂/P₁) = (ΔH_vap)/R * (1/T₁ - 1/T₂)
• Compressibility Factor: Z = (p*V_m)/(R*T)
• Peng-Robinson Equation of State:  p = (R*T)/(V_m - b) - (a*α)/(V_m² + 2*b*V_m - b²)
• Reduced Specific Volume:  v_r = v/(R* T_cr / P_c)
• Van't Hoff Equation:  ΔH⁰ = R * ( -ln(K₂/K₁))/ (1/T₁ - 1/T₂)

Supplement Material

• Khan Academy:Rate of reaction, Rate law and reaction order, Finding units of rate constant k
• ChemPrime:Reaction Mechanisms
• UC Davis:Using Graphs to Determine Rate Laws,Methods of Determining Reaction Order,Reaction Mechanisms

References

[1]https://en.wikipedia.org/wiki/Rate_equation

[2]Whitten, et al. 10th Edition. Pp. 626, 629,631