Alcohols, Halogenoalkanes and Analysis Flashcards
Primary Alcohol
-OH group is attached to a carbon with one methyl group attached
General formula for alcohols
CnH2n+1OH
Secondary Alcohol
-OH group is attached to a carbon with two methyl groups attached
Tertiary Alcohol
-OH group is attached to a carbon with three methyl groups attached
Volatility of Alcohols
Low
Because the hydrogen bonds between the molecules need a lot of energy to break
[the tendency to evaporate]
Alcohols Miscibility with Water
Hydrogen bonds form between the -OH group and the water.
As alcohols increase in size their miscibility decreases
Bc larger molecules are mainly made up of the non-polar carbon chain
Uses of Ethanol
In alcoholic drinks
As a solvent in the form of methylated spirits
Uses of Methanol
As a petrol additive to improve combustion
As a feedstock in production of organic chemicals
Steam Hydration of Ethene
C2H4 + H2O –> C2H5OH
300 degrees
60 atm
H3PO4
Fermentation
C6H12O6 –> 2C2H5OH + 2CO2
yeast
37 degrees
Dehydration of Alcohols
ethanol –> ethene + water
170 degrees
acid catalyst- H3PO4 or H2SO4
Oxidising agents
K2Cr2O7
H2SO4
Oxidising a Primary Alcohol
First oxidised to a aldehyde
Oxidised further to a carboxylic acid [reflux]
Oxidising to an Aldehyde
Distillation
ethanol + [O] –> ethanal + water
Oxidising to a Carboxylic Acid
Heated under reflux, higher temperatures
ethanol + 2[O] –> ethanoic acid + water
