Chemical Kinetics
Chemical Kinetics
We use DH to tell if a rein is energetically possible or not
we use k to tell if a rain is product or reactant based
But this gives us no info on how 2 how fast the rain goesfrom reactants to products
Kinetics is the studyof reactionrates or their relation to the way the rain proceeds mechanism
Run rates
Chemicalkinetics concerns how rates of chemical rains are measured
the rate of rain describes how the concentration of a reactant or product changes with time in Mls
factors affectingRates
rate 2 collision frequency z energy
1 Concentration of reactants
2 Physical state of reactants
3 Temperature
4 Addition of Catalyst
Determining Reaction Rate
rate My D A is B
ist ist
A B
wewant therate to be ve sofor reactants thesign is ve DEFT L O
, General Rate of Reaction
art BB cc DD
Reaction rate rate of disappearance of reactants Reaction rate rate of formation of products
rate DEA AEB Los rate DEC BED
a ist bist Cgt dat
Rate Laws
for the general reini aA BB cc DD
b rate K A B x a y b x ay mustbe determinedexperimentally it can be rel ve
K is therateconstant
k depends on
1 the rain
2 the temperature
3 the presence of a catalyst
the unit of K depends on the overall order of the reactioni
1 the sum of all exponents in the rate law Cxty
2 rate K A CB in this example the rain is said tobe x orderin A s y order in 13
Experimental kinetics
1 Method of InitialRatesi good for slow rains
2 Graphical method good for fast rains
3 Isolationexperimentsi good forintermediate or complex Mins
The method of initialrates
Ideai vary the concentration of a reagent observe its effect on theinitialrate
Chemical Kinetics
We use DH to tell if a rein is energetically possible or not
we use k to tell if a rain is product or reactant based
But this gives us no info on how 2 how fast the rain goesfrom reactants to products
Kinetics is the studyof reactionrates or their relation to the way the rain proceeds mechanism
Run rates
Chemicalkinetics concerns how rates of chemical rains are measured
the rate of rain describes how the concentration of a reactant or product changes with time in Mls
factors affectingRates
rate 2 collision frequency z energy
1 Concentration of reactants
2 Physical state of reactants
3 Temperature
4 Addition of Catalyst
Determining Reaction Rate
rate My D A is B
ist ist
A B
wewant therate to be ve sofor reactants thesign is ve DEFT L O
, General Rate of Reaction
art BB cc DD
Reaction rate rate of disappearance of reactants Reaction rate rate of formation of products
rate DEA AEB Los rate DEC BED
a ist bist Cgt dat
Rate Laws
for the general reini aA BB cc DD
b rate K A B x a y b x ay mustbe determinedexperimentally it can be rel ve
K is therateconstant
k depends on
1 the rain
2 the temperature
3 the presence of a catalyst
the unit of K depends on the overall order of the reactioni
1 the sum of all exponents in the rate law Cxty
2 rate K A CB in this example the rain is said tobe x orderin A s y order in 13
Experimental kinetics
1 Method of InitialRatesi good for slow rains
2 Graphical method good for fast rains
3 Isolationexperimentsi good forintermediate or complex Mins
The method of initialrates
Ideai vary the concentration of a reagent observe its effect on theinitialrate
