化学动力学（Chapter 5）

这是一篇关于化学动力学（Chapter 5）的思维导图，主要内容包括：Rates of Chemical Reaction。

化学动力学（Chapter 5）

• Rates of Chemical Reaction
  • 5-1 Rates and Mechanisms of Chemical Reactions
    • 5-1.1 The Rate of Chemical Reaction
      • • the decrease in concentration of a reactant
        • increase in concentration of a product in a unit of time.
        • units
      • average reaction rate
      • Instantaneous rate:
    • 5-1.2 The Mechanisms of Chemical Reactions
      • Reaction Mechanisms
        • a description of the path that a reaction takes.
      • Overall reaction
        • A reaction was completed through several elementary reactions.
      • Elementary reaction（基元反应）:
        • A reaction can complete directly by only one step or reactants can convert into products.
          • unimolecular
          • bimolecular
          • termolecular
  • 5-2 Theories of Reaction Rate
    • 5-2.1 Collision Theory and Activation Energy
      • Contents of Collision Theory
        • ⑴ reacting molecules must come so close that they collide.
        • ⑵ not every collision between molecules creates products, only few collisions between reactant molecules will react.
        • ⑶ enough energy; proper orientation
          • For a collision to result in reaction, the molecules must be properly oriented.
          • Collisions must occur with enough energy to break the bonds in the reactants so that new bonds can form in the products.
      • 活化理论
        • •Activation molecule
          • is the molecule have enough energy and can produce effective collision
        • activation energy (Ea） :
          • The minimum energy of a collision that leads to a reaction.
            • Figure: As the activation energy of a reaction decreases, the number of molecules with at least this much energy increases, as shown by the yellow shaded areas.
    • 5-2.2 The Transition StateTheory
      • Transition state theory (TST)（activated complex theory.）
        • reactants pass through high-energy transition states before forming products, they are associated in an unstable entity called an activated complex, then change into products.
  • 5-3 Reaction Rates and Concentrations
    • 5-3.1 The Rate Law
      • • ① when [A]=[B]=1mol·L-1 , v=k
        • ② the greater the k , the faster the rate
        • ③ m and n must be determined experimentally, in general, m and n are not equal to the stoichiometric coefficients a and b
    • 5-3.2 Order of A Reaction
      • • m is the order of the reaction with respect to A
        • n is the order of the reaction with respect to B.
        • The overall order of the reaction is the sum of m and n
      • • First-order reactions
      • • Second - order reactions
        • A,B初始浓度为一样
      • • Zero - order reactions
  • 5-4 Effect of Temperature on Reaction Rates
    • 5-4.1 Rule of Thumb ( Van ’ t Hoff Law)
    • 5-4.2 The Arrhenius Equation
    • 5-4.3 Application of Arrhenius Equation
  • 5-5 Effect of Catalyst on Reaction Rates
    • • Catalyst:
      • is a substance that increase the rate of a chemical reaction without itself being consumed (changed).
        •  The features of catalysts
          • • No change of mass and composition
          • • Selective
          • • Small amount can have big action
          • • Not only speed forward reaction but also speed reverse reaction ( effect velocity , not effect equilibrium constant )
        • three types:
          •  Homogeneous catalysis
          •  Heterogeneous catalysis
          •  Enzyme Catalysis
            • Gentle
            • High efficient
            • High selective (special)
• The characteristics of zero-order reactions：
  • 1. A graph of c against t is a straight line
  • 2. The rate constant, k, has units of [c][t]-1；
  • 3. The half-life of a zero-order reaction is t1/2=0.5c0 /k.
• The characteristics of second- order reactions：
  • 1. A graph of 1/c against time is a straight line , the slope of which gives the rate constant for the reaction；
  • 2. The rate constant, k, has units of [c]-1[t]-1；
  • 3. The half-life of 2th-order reactions
• The characteristics of first-order reactions：
  • 1 . A plot of logc versus t (time) gives a straight line with a slope of -k/2.303
  • 2. The rate constant, k, has units of [time]-1 .
  • 3. half-life (t1/2) :
• effective collision: a collision that leads to a reaction