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CHEMISTRY 1622008
4
th
WEEK RECITATION
ANNOUNCEMENTS
EMAIL
ATTENDANCE
•
Sign in
EXAMS
•
1
st
hourly: Wed., Feb. 20
th
, 9:4011:00 PM.
•
Review session:
Thursday, Feb. 14
th
, 8:0010:00 PM, CDL 102
Chapter 12  Solutions
Sunday, Feb. 17
th
, 8:3010:30 PM, Hck 138
Chapter 13  Kinetics
QUIZ
•
Lect. and rec. quizzes graded; pickup after class.
•
Hold onto all quizzes until end of semester.
Chem 1622008 4th week recitation
1
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View Full Document PLAN FOR TODAY
:
CHAPTER 13 (cont.)  CHEMICAL KINETICS
•
Temperature dependence of rate constant (Arrhenius equation)
•
Reaction mechanisms
CHAPTER 14 – CHEMICAL EQUILIBRIUM*
•
The equilibrium constant
•
Equilibrium calculations
* Easy, but extremely important; basics for chapters 14, 15 & 16
Chem 1622008 4th week recitation
2
FORMULAS
C
12
H
22
O
11
+ H
2
O > C
6
H
12
O
6
+ C
6
H
12
O
6
Rate of sucrose disappearance = (∆ [sucrose])/(∆ time) =
([sucrose
f
] – [sucrose
i
])/(t
f
– t
i
)
aA + bB > cC + dD
General rate of reaction = (1/a)(∆[A]/∆t) = (1/b)(∆[B]/∆t) = (1/c)(∆[C]/∆t) = (1/d)(∆[D]/∆t)
Determination of order of reaction through method of initial rates:
For a single reactant:
Rate 1 = k[A
1
]
m
Rate 2 = k[A
2
]
m
(Rate 1/Rate 2) = (k[A
1
]
m
)/(k[A
2
]
m
) = ([A
1
]/[A
2
])
m
For two reactants:
Rate1 = k[A
1
]
m
[B
1
]
n
Rate2 = k[A
2
]
m
[B
1
]
n
(Rate1/Rate2) = (k[A
1
]
m
[B
1
]
n
)/(k[A
2
]
m
[B
1
]
n
) = (A
1
/A
2
)
m
Integrated
Reaction
Differentiated
rate law
k
Order
Reaction Rate**
RATE LAW***
(y
=
mx + b)
Halflife
*
units
0
Rate = (C
2
C
1
)/(t
2
t
1
)
Rate = k[C]
o
=k
[C]
t
= kt
+ [C]
o
t
1/2
= [C]
o
/2k
M
1
s
1
1
Rate = (C
2
C
1
)/(t
2
t
1
)
Rate = k[C]
1
ln[C]
t
= kt + ln[C]
o
t
1/2
= 0.693/k
M
o
s
1
2
Rate = (C
2
C
1
)/(t
2
t
1
)
Rate = k[C]
2
1/[C]
t
=
kt + 1/[C]
o
t
1/2
= 1/(k[C]
o
)
M
1
s
1
** Rate of appearance = +slope; rate of disappearance = rate of appearance = slope.
*** Differentiated Rate Law may be for more than one component, e.g., Rate = k[C]
1
[D]
2
*Halflives
:
For a zero order reaction, each successive halflife is ½ the preceding one.
For a first order reaction, each successive halflife is equal to the preceding one.
For a second order reaction, each successive halflife is double the preceding one.
Arrhenius equation:
k = Ae
(Ea/RT)
;
ln k = ((E
a
/R) x (1/T)) + ln A
A = frequency factor = combination of steric factor and collisional frequency
E
a
= energy of activation
ln k
2
– ln k
1
= (E
a
/RT
2
) – (E
a
/RT
1
)
Chem 1622008 4th week recitation
3
ln k = E
a
/RT + ln A
ln (k
2
/k
1
) = (E
a
/R)[(1/T
2
)  (1/T
1
)]
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View Full Document COLLISION THEORY, INCLUDING ARRHENIUS EQUATION
ET: What factors affect the reaction rate?
Rate = k[A]
m
[B]
n
.
Concentration of reactants, reaction order and k affect the rate.
ET: Draw curve showing that
higher concentration = higher rate.
ET: What affects the rate constant?
Qualitatively: Collision Theory is built around the central idea that for molecules to react they must (1) collide, (2) have
the right energy, (3) have the right geometry.
ET: What affects the rate constant? Quantitatively: Arrhenius equation.
Discuss Ea.
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This note was uploaded on 09/23/2009 for the course CHEM 162 taught by Professor Siegal during the Spring '08 term at Rutgers.
 Spring '08
 siegal

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