Chemistry Chap 14

Physical state of reactants

In solid form do not react but once in solution react rapidly

Concentration of reactants

M/S rate increases solid < Liquid < Gas

increasing the concentration should increase the rate of rxn

Temp at which rxn occurs

high temp usually increases the rate of rxn

Presence of catalyst

EA decreases, catalyst speed up a rxn without being used up

Instantaneous Rate

actual rate at any given instant

Average Rate

rate determined from the difference in concentration of reactant or product over a period of time

Initial rate method

shows the relationship between initial concentration and initial rates

Integrated Rate Law Method

uses calculus to change the rate law into an equation showing how concentration varies with time

Zero order Rate laws

1. rxn rate is not dependent on the concentration of nay of the reactants rate = k

2. two important examples

   a. Heterogenous catalysis

   where a metal surface is required for a rxn to occur

   b. rxn involving enzymes in living systems

Auto Catalytic converters

Gas molecule must contact the metal surfaces in order to react and does not affect the rate of the rxn

First order Rate Laws

the rate is proportional to the concentration of the reactant [A] → products

A+B→C+D