Chapter 9 and 22 Vocab

1. %%Rate of Reaction%%- a measure of the rate at which reactants are used up or the rate at which products are formed; the units of rate are mol\*/((dm^3)*s), rate = (change in amount of reactants/products)/ (time).*
2. %%Collision Theory%%- In order to react w/ e/o, particles must collide in the correct orientation and w/ sufficient energy, the particles may be atoms, ions, or molecules.
3. %%Activation Energy%%- the minimum energy that colliding particles must possess for successful collision that results in a reaction to take place, denoted E\[subscript a\].
4. %%Catalyst%%- A substance that increases the rate of a reaction but remains chemically unchanged itself at the end of the reaction.
5. %%Boltzmann Distribution%%- A graph showing the distribution of energies of the particles in a sample at a given temperature.
6. %%Enzyme%%- A protein molecule that is a biological catalyst; most act on a specific substrate.
7. %%Substrate%%- A molecule that fits into the active site of an enzyme and reacts.

(Chapter 22 begins)
8. %%Rate constant%%- The proportionality constant in the rate equation, denoted k.
9. %%Rate Equation%%- An equation showing the relationship between the rate constant and the concentration of those reactants that affect the rate of reaction; the general form of the equation is: rate=k(\[A\]^m)(\[B\]^n) where k is the rate constant, \[A\] and \[B\] are the concentrations of those reactants that affect the rate of reaction, m is the order of the reaction w/ respect to A and n is the order of reaction w/ respect to B.
10. %%Order of Reaction%%- The power to which the concentration of a reactant is raised in the rate equation; if the concentration does not affect the rate, the reaction is **zero order**; if the rate is directly proportional to the reactant concentration, the reaction is **first order**; if the rate is directly proportional to the square of the reactant concentration, the reaction is **second order**.
11. %%Half Life (t[subscript 1/2])%%- The time taken for the amount (or concentration) of the limiting reactant in a reaction to decrease to half its value.
12. %%Rate Determining Step%%- The slowest step in a reaction mechanism.
13. %%Homogeneous Catalyst%%- The type of catalysis in which the catalyst and reactants are in the same phase; for example, sulfuric acid catalyzing the formation of an ester from an alcohol and carboxylic acid (both reactants liquid).
14. %%Heterogeneous Catalyst%%- The type of catalysis in which the catalyst is in a different phase from the reactants, for example, iron in the Haber process.
15. %%Adsorption (in catalysis)%%- The first stage in heterogeneous catalysis; molecules of reactants (usually gases) form bonds with atoms on the surface of the catalyst.
16. %%Desorption%%- The last stage in heterogeneous catalysis; the bonds holding the molecule(s) of product(s) to the surface of the catalyst are broken and the product molecules diffuse away from the surface of the catalyst.
17. %%Instantaneous Rate of Change%%- The rate of reaction at any particular point in time.

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