CHEM10006 Study Guide - Final Guide: Chemical Kinetics, Photolyase, Reagent
12 Jun 2018
School
Department
Course
Professor
2nd law of thermodynamics:
Whenever a spontaneous event takes place,
the total entropy of the universe
increases/universe tends towards disorder
Factors that affect entropy
●volume
●temperature
●physical state
Rate of reaction
Van’t Hoff’s equation: used to calculate K at
a specified temperature if the value of K at
another temperature is known
Reaction kinetics: factors that influence rate of reaction:
●Concentration of reactants
●Temperature of system: increases with greater temperatures
●Presence of a catalyst
●General rate law: rate is inversely proportional to [Reactant]: Rate = k[A]
x
where x is
the order and K is the rate constant: only affected by the presence of a catalyst or
temperature
Zero order reactions
1st order reactions
2nd order reactions
Changes in concentration
will not affect the rate of
reaction e.g. 3
0
= 1
Half life is directly
proportional to [A]
0
but
inversely to K
If you double the
concentration the rate will
double, e.g. 2
1.
=2, 3
1
= 3, if
you increase concentration
by a factor of 4, the rate will
increase by a factor of 4
Whatever change is applied
to the reactant, the rate
change will be the square of
the amount you changed it
by, e.g. 2
2
= 4, 3
2
= 9, where
rate increases by a factor of
4 & 9 respectively
Half life: As [A]
-0
increases,
half life decreases (inversely
proportional)
●Enzyme catalysts: DNA photolyase (repair of UV damage to DNA), catalase
(decomposition of H
2
O
2
), amylase (hydrolysis of starch to sugars)
Michaelis-Menten Enzyme Kinetics
Rate
1
= K
1
[E][S]
Rate
2
= K
2
[ES]
When [S] is low, can neglect it in
denominator and rate of reaction is
proportional to [S]
ES undergoes a slow irreversible change into
the product molecule, regenerating the
enzyme
Rate represents rate of product formation
[ES] found using Steady State
Approximation: complex reaches a steady
value during the reaction; [ES] is constant
Hess’s law: Regardless of the multiple stages or steps of a reaction, the total enthalpy change
for the reaction is the sum of all changes
Chemical equilibrium: The state of a chemical reaction in which its forward & reverse reactions
occur at equal rates so that the concentration of the reactants & products does not change
with time
Document Summary
Whenever a spontaneous event takes place, the total entropy of the universe increases/universe tends towards disorder. Van"t ho "s equation: used to calculate k at a speci(cid:1560)ed temperature if the value of k at another temperature is known. Reaction kinetics: factors that in uence rate of reaction: Temperature of system: increases with greater temperatures. General rate law: rate is inversely proportional to [reactant]: rate = k[a] x where x is the order and k is the rate constant: only a(cid:1559)ected by the presence of a catalyst or temperature. Changes in concentration will not a ect the rate of reaction e. g. 3 0 = 1. Half life is directly proportional to [a] 0 but inversely to k. If you double the concentration the rate will double, e. g. 2 1. =2, 3 1 = 3, if you increase concentration by a factor of , the rate will increase by a factor of .
