chem 336 - 338 lab lecture c 336-01 organic chemistry laboratory ii and
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Chem 336 - 338 Lab Lecture C 336-01 Organic Chemistry Laboratory II and C 338-01 Organic Chemistry Laboratory II Honors. Dr. Margareta Séquin Office : Science 106C; Office Hours : Tu 11-12 pm, Th 1-2 pm and by appt. e-mail : msequin @ sfsu.edu Phone: 415-405-0315. - PowerPoint PPT PresentationTRANSCRIPT
Chem 336 - 338 Lab LectureChem 336 - 338 Lab Lecture
C 336-01 Organic Chemistry Laboratory II and
C 338-01 Organic Chemistry Laboratory II Honors
Dr. Margareta Séquin
Office: Science 106C; Office Hours: Tu 11-12 pm, Th 1-2 pm and by appt.
e-mail: msequin @ sfsu.edu
Phone: 415-405-0315
First half of semester: Syntheses and methods of evaluation
Second half: C336 “Unknowns”. C338 Final Project
Prerequisites: C336: passing grade (C or better) in Chem 333, 334; Chem 335 (can be taken concurrently). C338: B or better. Prerequisites will be strictly applied.
A student who withdraws from Chem 335 must also withdraw from Chem 336 or Chem 338.
Text: “Chem 334, 336, and 338 Organic Chemistry Laboratory”, SFSU 2005, with Mayo, Pike, Trumper, "Microscale Organic Laboratory", 4th Ed.; Wiley Custom Ed.
Use your lecture text for reference!
GradingC336 and C338: MiniQuizzes at the end of lab lectures, 2 pts. each C336 and C338: One Midterm Exam (100 points) C336: Final Exam (150 pts.) C338: Special Project Final Report, worth 150 pts.
Lab reports: 20 points/ lab report 1 - 4. Lab reports V and VI will be combined and will be 30 pts. Unknown reports (C336) will be 30 pts. each.
Lab Notebooks will be checked regularly. Your total class grade will be calculated as follows: 40% Exams % (Midterm, plus Mini Quizzes, plus Final Exam or Project, %) 30% Lab reports % 30% Lab preparation, notebook, effort, attendance, participation.
Total class grade: >/=90% A; 85 -<90% A-; 80 -<85% B+; 75 -<80% B; 70 -<75% B-; 65 -<70% C+; 60 -<65% C; 55 -<60% C-; 50 -< 55% D+; 45 -<50% D; 40 -<45 D-; <40% F
Exp.1: Solvolysis of tert Butyl Chloride CCH3
CH3
CH3
Cl + H2O + HClCCH3
CH3
CH3
OH
1. IUPAC name for tert butyl chloride, for the alcohol product?
2. Why does changing the solvent medium affect the rate?
60%water:40%acetone; 70%water:30%acetone; 80%water:20%acetone
See Helpful Websites and your lecture text and:http://www.cem.msu.edu/~reusch/VirtualText/alhalrx2.htm#hal5
Measuring the tenth–life in our reaction
What is a possible by-product of our reaction? Does this affect our data?
How would a one-third decrease of concentration of RX affect the reaction rate?
CCH3
CH3
CH3
Cl + H2O + HClCCH3
CH3
CH3
OH
Calculations for Exp.1: Solvolysis of tert Butyl Chloride Reaction Rate = =
-d(reactant)
dt-d[RCl]
dt= k[RCl]
p.354-355
CCH3
CH3
CH3
Cl + H2O + HClCCH3
CH3
CH3
OH
Calculations for Exp.1: Solvolysis k dt
t
0=
[RCl]
d[RCl][RCl]
[RCl]o
-
= k dt-d[RCl]
[RCl]
dt
-d[RCl]= k[RCl]
= kt-ln [RCl]
[RCl]o
1.
2.
3.
4.
Calculations for Exp.1: Solvolysis = kt-ln
[RCl]
[RCl]o
at t10%, [RCl] = 0.90 [RCl]o = kt 10%-ln
0.90[RCl] o[RCl] o
-ln = kt 10%0.90 = 0.1053
0.1053
t10%= k
Units of k?
How could you calculate k by using the half life?
Arrhenius Equation and Calculation of Ea and A k = A e
-Ea/RT
What does Ea tell us about the reaction?
ln k = ln A -Ea/RT
Plot ln k vs. 1/T for each solvent mixture
ln k
1/T
y = b + m x
R=1.987216 cal/K mol
Arrhenius Plots
y = -13082x + 38.64
y = -12362x + 35.503
y = -11872x + 32.619
-10
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
0.0032 0.00325 0.0033 0.00335 0.0034 0.00345 0.0035 0.00355
1/T (Kelvin)
ln (k
)
60/40
70/30
80/20
Next time:
• Kinetics (conclusion)• Friedel-Crafts (Exp.2)
• MiniQuiz on today’s class (Exp.1)
Please fill out roll form and hand it in. Thank you.