O1: Alkenes + Alcohols Flashcards
What is the alcohol functional group?
-OH
Hydroxyl group
What is the general formula for an alcohol?
CnH2n+1OH
How would you write a structural formula including an alcohol?
With brackets
e.g CH3CH(OH)CH2CH3
By what process takes a halogenoalkane to an alcohol?
Nucleophilic Substitution
What is the suffix for an alcohol?
-anol
e.g Butan-2-ol
How can alcohols be classified?
Primary, secondary, tertiary
-According to the number of carbons bonded to the C-OH bond
e.g P= 1 S=2 T=3
What is a diol?
An alkane where 2 of the hydrogens have been replaced by an -OH group.
What is the suffix of a diol?
-diol
e.g Hexane-2,2-diol
What are the properties of alcohols?
-All have VDW forces
-Have hydrogen bonding (very strong) between to -OH groups (the H and the O)
-The longer the carbon chain, the higher the boiling point (more VDW forces)
-Smaller ones are soluble in water as alcohols are polar due to the negative O. As chain length increases, solubility decreases as a greater region is non-polar (carbon chain)
What is a carbonyl group?
A carbonyl compound if there is a C=O in the molecule.
Describe Aldehydes
-Carbonyl group is bonded to a C and a H, or a H and a H
-They will always be on the end of a molecule
-General Formula: CnH2nO
-Structural: RCHO
-Suffix: -anal
Describe Ketones
-Carbonyl group bonded to C and C
-Always be in the middle of a molecule (position number needed)
-General formula: CnH2nO
-Structural: e.g CH3C O CH3 always after the C its bonded to
-Suffix: -anone
Describe Carboxylic Acids
-Carbonyl group bonded to a C and OH, or H and OH
-Always at the end of a molecule
-General formula: CnH2n+1COOH
-Structural: RCOOH
-Suffix: -anoic acid
What are the properties of Carbonyl Compounds?
-All have a C=O bond, O is more negative
-Aldehydes, ketones, and carboxylic acids all have VDW and dipole-dipole forces due to the negative O.
-Hydrogen bonding occurs in Carboxylic acids due to the O-H
This means:
-Aldehydes and ketones have similar MP and BP, but carboxylic acids have higher ones
-As chain length increases strength of VDW increases, so dos MP and BP
Are carbonyl compounds soluble?
-All are polar, and like dissolves like, so very soluble in water
-Smaller compounds are more soluble, larger ones less as there is a greater region of non-polar.
-Carboxylic acids are more soluble than aldehydes and ketones as they have an -OH group to form hydrogen bonds with water.
What do primary alcohols get oxidised to?
Aldehydes
Then oxidised again to carboxylic acids (as they have another C-H bond to break)
What are Secondary alcohols oxidised to?
Ketones
What are tertiary alcohols oxidised to?
Cannot be oxidised as they do not have a C-H bond to break
What is an Oxidising agent?
Accepts electrons
What oxidising agent is used to oxidise alcohols?
Acidified Potassium Dichromate (K2Cr2O7)