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Today’s Lecture• Block 1: Mole Balances (Review)
Size CSTRs and PFRs given –rA=f(X)
Conversion for Reactors in Series• Block 2: Rate Laws
Reaction Orders
Arrhenius Equation
Activation Energy
Effect of Temperature • Block 3: Stoichiometry Stoichiometric Table Definitions of Concentration Calculate the Equilibrium Conversion, Xe
Review of Mole Balances
Review of Conversion
A general reaction:
fedA moles
reactedA moles X
D a
d C
a
c B
a
b A
ncalculatio of basis asA reactant limiting Choose
D d C c B b A a
Levenspiel Plot (Review)
FA 0
rA
X
CSTR(Review)
FA 0
rA
X
Area = Volume of CSTR
X1
V FA 0
rA
X1
X1
PFR(Review)
FA 0
rA
Area = Volume of PFR
V 0
X1FA 0
rA
dX
X1
Reactors in Series (Review)
Two steps to get
Step 1: Rate Law
Step 2: Stoichiometry
Step 3: Combine to get
rA f X
rA g Ci
Ci h X
rA f X
1010
Collision Theory
When one substance is mixed with another, the two substances ….
According to collision theory, atoms, ions, and molecules can react to form ...
Rates of chemical reactions are often measured as ...
1515
The factors that affect how ...
1616
Factors influencing the likelyhood of a reaction occurring:
1)
1717
2)
1818
3)
1919
2020
2121
2222
In order for the reaction to occur, the particles involved must collide with each other, …………………………………………………………. Not every collision results in a reaction.
activated complex
The …………………is the temporary arrangement of atoms as they change from reactants into products.
2323
Orientation
2424
The colliding molecules must have enough energy to react and form an ……………. This minimum amount of energy is called the …………..
activation energy
2525
Rate of a Reaction = speed of reactants turning into products
Can be measured in :
or
2626
2727
Effect of the Nature of the Reactant
The nature of the reactants involved will determine the kind of reaction that occurs.
Reactions with bond rearrangements or electron transfer take longer than reactions
without these changes……
2828
Effect of Temperature on Reaction Rate
Increasing the temperature increases
the rate of a reaction. At higher temperatures, the particles have more energy, move faster and collide more
frequently. ….
2929
Effect of Concentration on Reaction Rate
Increasing the concentration of the reactants increases the rate of a
reaction. …..
3030
Effect of Particle Size/Surface Area
Decreasing particle size/increasing surface area increases the rate of a
reaction. When ….
3232
Not Cattle List!!
3333
Catalyst - any substance that is added to the reaction to ………
the rate. The catalyst ……….. react with any substance to produce product.
Inhibitor - Any substance added to ………. the rate of reaction.
Works against the catalyst.
3434
C2H2
H2 C2H4
3535
A catalyst increases the rate of a reaction by lowering the activation energy.
3636
Stoichiometry
Batch Systems
Batch Systems (Stoichiometric Table)
Batch Systems (Constant Volume)
Batch Systems (Example)
Exp
ress
ing
conc
entr
atio
n as
a
func
tion
of c
once
ntra
tion
Example 1
Example2
Homework1
Homework2
Homework3