Objectives: What does reaction order mean? What is an integrated rate law and how / when is it used?

Zero Order Reactions: Reactant conc. DOES NOT effect the rate of the reaction Slope is constant at all times (rate is constant at all times) Half life decreases

Zero Order Reactions: Rate Law: rate = k for ALL 0 order reactions

First Order Reactions: Reactant conc. DOES effect the rate of the reaction The reaction slows down as M decreases Half life stays constant!

First Order Reactions: All nuclear decay processes are first order

First Order Reactions: Example: The decomposition of H2O2 into H2O and O2 is a common first order process

Second Order Reactions: Reactant conc. has a larger effect on the rate of the reaction These reactions start fast but slow down quickly as molarity decreases Half life gets longer!

Integrated Rates Laws The wonders of calculus allow us to turn standard rate equations … rate = k [reactants] into integrated rate equations … for 1st order reactions  for 2nd order reactions 

Integrated Rates Laws for 1st order reactions for 2nd order reactions These equations allow us to make predictions about how concentration of reactants change over time WITHOUT using a graph

Do now: Read through “the calculus”

Integrated Rates Laws Cyclopropane, an old school anesthetic, decomposes to form propene where the rate=k[cycloprop] and k=2.42 h-1 at 500oC. If the initial concentration of cyclopropane is 0.050 mol/L, how much time must elapse for the concentration to drop to 0.01 mol/L?