1. Rate Law
Main Concept:
The rate law shows how the rate depends on reactant concentrations.

2. Rate Law Rate Law Defined Reaction Orders How to Determine
Graphical Representations

3. - rate law: expresses rate of reaction as proportional to concentration of each reactant raised to a power
- power of each reactant in rate law is order of reaction with respect to that reactant
- sum of powers of reactant concentrations in rate law is overall order of reaction

4. - When rate is independent of concentration for a reactant, reaction is zeroth order for that reactant, since raising reactant concentration to power zero is equal to the reactant concentration being absent from rate law

5. - In cases where concentration of any other reactants remain essentially constant during reaction, the order of a reaction with respect to a reactant concentration can be inferred from plots of concentration of reactant versus time

6. Negatively sloped straight line with [A]
Zeroth Order Reaction
Negatively sloped straight line with [A]

7. Negatively sloped straight line with ln [A]
First Order Reaction
Negatively sloped straight line with ln [A]

8. Positively sloped straight line with 1/[A]
Second Order Reaction
Positively sloped straight line with 1/[A]

9. Zeroth Order 
 First Order
Second Order 

10. Question:
Looking at the “Kinetics” section of the reference pages available to you, what order are these two equations that are given to you? What might they allow you to do?

11. [A]t – [A]0 = – kt 0th order 1st order 2nd order
These are presented on your reference page in this order, so…
[A]t – [A]0 = – kt 0th order
1st order
2nd order

12. - method of initial rates is useful for developing conceptual understanding of what a rate law represents
- Investigation of data for initial rates enables prediction of how concentration will vary as reaction progresses

13. Rate Constant Main Concept:
The magnitude and temperature dependence of the rate of reaction is contained quantitatively in the rate constant.

14. - proportionality constant in rate law = rate constant, k
- rate constant is a measurable quantity that characterizes a chemical reaction
- Rate constants vary over many orders of magnitude because reaction rates vary widely

15. - temperature dependence of reaction rates is contained in temperature dependence of rate constant
- For first-order reactions, half-life is often used as a representation for rate constant because they are inversely proportional, and half-life is independent of concentration. For example, radioactive decay processes

16. Zero Order First Order Second Order
*** Half-life equation doesn’t work for zero or second order reactions
Zero
Order
First Order
Second
Order