Chapter 14 - Alcohols Flashcards
(18 cards)
What is the general formula of alcohols?
CnH2n+1
What are the 2 methods that can form an alcohol?
- Fermentation
- Hydration
What are the 3 ways of classifying alcohols?
- Primary alcohols
- Secondary alcohols
- Tertiary alcohols
Why do alcohols have high boiling points?
- Alcohols are polar molecules due to the -OH bond
- This means it can form hydrogen bonds
- Hydrogen bonds are strong and therefore require large amounts of energy in order to break the bonds
How to classify a primary alcohol?
The -OH group is attached to a carbon atom that is attached to 2 hydrogens
How to classify a secondary alcohol?
The -OH group is attached to a carbon atom that is attached to one hydrogen atom
How to classifiy a tertiary alcohol?
The -OH group is attached to a carbon atom that is attached to no hydrogen atoms
What is the oxidising agent for the oxidation of alcohols?
K2Cr2O4 / H2SO4
What can primary alcohols be oxidised to?
Aldehydes and Carboxylic acids
What is the colour change that indicates that an alcohol has been oxidised?
Orange to green
Partial oxidation of primary alcohols
Reagent : Acidifed K2Cr2O7
Conditions : Distillation
Product : Aldehyde + Water
Full oxidation of primary alcohols
Reagent : Acidified K2Cr2O7
Conditions : Reflux, excess dichromate
Product : Carboxylic acid + Water
Oxidation of Secondary alcohols
Reagent : Acidifed K2CrO7
Conditions : Reflux
Product : Ketone + Water
Can tertiary alcohols be oxidised?
No
Define ‘Dehydration’
Any reaction in which a water molecule is removed from a compound
Dehydration of an alcohol
Reagent : Acid catalyst (H2SO4 or H3PO40
Conditions : Reflux and heat
Product Alkene + water
What is the name of the reaction between an alcohol and a hydrogen halide to form a haloalkane?
Substitution reaction
Substitution of alcohols:
Reagents : H2SO4 and Sodium Halide
Conditions : Reflux
Products : Haloalkane + Water
