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Prelab Lecture
SN1 (Solo Exp#2)
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BACKGROUND READING:Solomons and Fryle Chapter 6 (Sub/Elim Rxns)
Techniques Weights/Measures, Filtration, Melting Point, TLC
Videos Filtration Vacuum, Melting Point, TLC
CHEM 212 PRELAB CYCLE 1 SN1
Laura Pavelka
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SN1 Reaction
PURPOSE: convert an alcohol to an alkyl chloride via an SN1 mechanism
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SN1 Reaction nucleophilic substitution
reaction with unimolecular rate
determing step (RDS)- RDS carbocation formation
tertiary carbocation
LG Nu
NuRDS
3 > 2 >>>> 1
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SN1 Experiment
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Acid Catalyzed SN1:
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IR Spectroscopy
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Solubility and
Thin Layer Chromatography (TLC)
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Cl
Cl
vs.
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Overview SN1 Lab
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PURPOSE: convert an alcohol (2,5dimethyl2,5hexandiol) to an alkyl
chloride (2,5dichloro2,5dimethylhexane),
learn new analysis techniques IR spectroscopy, TLC
2,5dimethyl2,5hexanediol 2,5dichloro2,5dimethylhexane
Analysis: Melting Point, IR Spectroscopy, Solubility, TLC
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1. SN1 Reaction
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2. Melting Point
MELTING POINT
physical property of a compound, index of purity
fixed value reported as a RANGE
CRUDE PURIFIED
MP VALUE depressed close to
literature
MP RANGE BROAD
(> 3oC)
NARROW
(1 3 oC)
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Cl
Cl
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2. Melting Point
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3. IR Spectroscopy
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Cl
Cl
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5. Thin Layer Chromatography
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Cl
Cl
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% Yield
CRUDE Theoretical
MASS 1.5 g 3.0 g
% YIELD (crude) = mass crude x 100% = 1.5 g x 100% = 50 %
theoretical 3.0 g
TOTALLY FICTICIOUS VALUES
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Safety & Waste Disposal
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Special Safety Considerations:
Hydrochloric acid (HCl) Hazardous in case of skin/eye contact, inhalation/ ingestion.
Corrosive.
Ethanol Hazardous in case of skin/eye contact, inhalation/ ingestion. Flammable.
Hexanes Hazardous in case of skin/eye contact, inhalation/ ingestion. Flammable.
Ethyl Acetate Hazardous in case of skin/eye contact, inhalation/ ingestion. Flammable.
Phosphomolybdic acid Hazardous in case of skin/eye contact, inhalation/ ingestion.
Toxic and corrosive. Will stain skin, wear gloves.
Waste Disposal:
Aqueous filtrate, product isolation: Acidic wasteIsolated Dichloro product: Collected in labeled bottle
Solubility Tests: Nonhalogenated organic waste
TLC mobile phase: Nonhalogenated organic waste
Pipettes: Glass waste