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CHM 219 Module 5 questions and answers verified answers||Latest 2024/2025
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CHM 219 Module 5 questions and answers verified answers||Latest 2024/2025
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CHM 219 Module 5Alcohol - ANSGeneric formula R-OH, defined by the presence of a Hydroxyl group (-OH).
Organic derivatives of water, as one of the hydrogen atoms from the water molecule is replaced
by an alkyl group.
Phenols - ANSHydroxyl group directly attached to a benzene ring
Methyl Alcohol - ANSOnly H atoms attached to the carbon bearing the-OH group
Primary Alcohol - ANSone alkyl group attached to the carbon atom bonded to the -OH group
Secondary Alcohol - ANSTwo alkyl groups attached to the carbon atom bonded to the -OH
group
Tertiary Alcohol - ANSThree alkyl groups attached to the carbon atom bonded to the -OH group
Boiling Point of Alcohols - ANSHigh due to Hydrogen bonding between the positively charged H
and negatively charged O
Water solubility of alcohols - ANSAs the carbon chain length increases alcohol becomes
correspondingly less soluble in water.
Alcohols Acidity/Basicity - ANSCan act as a weak base (accepting H+ using a lone pair on the O
atom) or weak acid (donating the O-H proton as H+)
Amphoteric - ANSa substance that can act as both an acid and a base
Alkoxide Ion - ANSconjugate base of an alcohol, very strong base
Alkyloxonium Ion - ANSThe conjugate acid of the alcohol is often called a protonated alcohol,
Dehydration - ANSLoss of water. An alcohol molecule will lose H2O to form an ALKENE. Type
of elimination reaction — lose the -OH from one C and H atom from the adjacent C.
First step — alcohol acts as a base.
Tertiary alcohols - E1
Primary alcohols - E2
All dehydration begins with... - ANSProtonation of the alcohol group.
Order of ease of dehydration of alcohol substrates... - ANS3>2>1
, Tertiary require the least harsh conditions (typically 25% aqueous acid and 60-80 degrees C)
whereas primary require fully concentrated acid and temperatures approaching 200 degrees C.
If more than one alkene product is possible... - ANSThe major product is the one whose C=C
has more alkyl groups attached.
ZAitsev's Rule - ANSThe production of the more highly substituted alkene as the major product.
Alcohols —> Alkyl Halides - ANS-Substitution REaction , replacing the -OH with a halogen
-Alcohol (R-OH) + Hydrogen Halide (H-X) ——> alkyl halide (R-X) + water (H-OH)
-the use of Hydrogen halides promotes the substitution in two ways
1. Acid protonates the -OH of the alcohol to make it a good leaving group
2. Halide ions are good nucleophiles but weak bases so substitution is promoted over
elimination
Order of Reactivity of Alcohols with HX - ANS3>2>1
Primary Alcohols react via.... (With HX) - ANSSn2
-OH group is protonated and then displaced as a water molecule by a chloride ion
Secondary Alcohols react via... (with HX) - ANSSn1 or Sn2 - depending on the structure of the
specific alcohol
Conversion using Phosphorous Halides (PX3) - ANSX= Cl or Br
- Alcohol (3R-OH) + phosphorous trihalide (X2P-X) —> alkyl halide (3R-X) + H3PO3
-particularly efficient as one molecule of PX3 can convert 3 molecules of alcohol to the
corresponding alkyl halide
-byproduct of the reaction is phosphorous acid
Conversion using Thionyl Chloride (SOCl2) - ANSAlcohol (R-OH) + Thionyl Chloride
(Cl-S=O-Cl) —> alkyl Chloride (R-Cl) + SO2 ^ + HCl
- very efficient with primary and secondary alcohols d/t the main byproduct (SO2) beig formed
as a gas and leaving the reaction mixture.
Oxidation to Aldehydes, Ketones and CArboxylic Acids - ANSOxidation - increasing the oxygen
content (number of oxygen atoms) or the oxygen character (more bonds to oxygen)
-Primary Alcohols —> aldehydes —> Carboxylic Acids
-SEcondary Alcohols —>ketones
-Tertiary - unreactive
Jones Reagent - ANSCromium Triioxide with aqueous sulfuric acid —> Chromic Acid
Disadvantage - strong oxidizer and wil not permit the synthesis of aldehydes from primary
alcohols
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