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Harrison Xu - Coggle Diagram

- - - - energy due to position or orientation
    - - Energy due to motion, KE = 1/2mv^2
    - - Energy is never destroyed nor created
      - Ties to 1st law of thermodynamics: energy is constant
- - - - Reaction rates are equal to derivative of concentration against time
      - Reaction rate can change to concentration
    - - Small reactants tend to react faster
      - Gas reactants react faster than liquids, faster than solids
      - Powdered solids react faster than blocks
      - Some chemicals are more reactive than others
      - Ions react faster than molecules
    - - The Chemist's rule states approx 10 deg C increase will lead to rate doubling
    - - There are positive catalysts, which increase rate
      - Negative catalysts reduce rate, and are sometimes called inhibitors
      - Catalysts can be homogeneous or heterogeneous
        
        Homogeneous catalysts are those that are in the same phase as the reactants
        
        Heterogeneous catalysts are those that are in different phase as the reactants
  - - - Differential rate law must be found experimentally
      - For a chemical reaction aA + bB -> ..., differential rate law is that rate = k[A]^n[B]^m
      - Single step reactions have orders that match the coefficients of the chemical reaction
        
        For ex, if we have a single step reaction 2NO(g) + O2(g) -> 2NO2(g), then the rate law would be rate = k[NO]^2[O2]
      - The overall order of a reaction is the sum of the orders of the reactants
      - To figure out the order of the reaction, you look at experimentation and see how much the rate changes in response to the change of the reactant concentration
      - When dealing with a rate law that has more than one reactant, it can be simplified by making a pseudo rate law
        
        Pseudo rate law can be created, if, for ex, we have rate = k[A]^n[B]^m[C]^p, then if we make [B] >> [A] and [C] >> [A], then [B] and [C] change the rate so little than they can be treated like constants, such that we can write rate = k'[A]^n
    - - Integrated rate laws differ for each order reaction
        
        Zero order: [A]_t = -kt + [A]_0
        
        First order: ln[A]_t = -kt + [A]_0
        
        Second order: 1/[A]_t = kt + 1/[A]_0
      - Integrated rate laws also have half lives, which differ depending on the order
        
        Zero order: t_1/2 = [A]_0/2k
        
        First order: t_1/2 = ln2/k
        
        Second order: t_1/2 = 1/k[A]_0
  - - - All elementary steps in a reaction mechanism are single steps
      - The rate law of a elementary step has order of the coefficients (remember this is true bc they're single steps)
    - - If I add all the elementary steps together, then they sum to the overall reaction
      - The rate law predicted by the mechanism must match the experimentally observed rate law
    - - If the slowest step includes an intermediate, then if the step before it is rapid equilibrium, then you can substitute the intermediate to find an actual rate law
  - - - There are unimolecular, bimolecular, trimolecular, etc. steps that exist
    - - Correct orientation
      - Sufficient energy