Alcohols And Carboxyllic Acids Flashcards
Large scale preparation of ethanol
Ethene + steam
300 degrees Celsius, 60-70atm, phosphoric acid catalyst
Gases cool, ethanol liquified
Unrelated gases recycled
Preparation of ethanol by fermentation
60 degrees Celsius, no air
C6H12O6(aq)–(yeast)–> 2CH3CH2OH(aq) + 2CO2(g)
How is ethanol removed?
Fractional distillation
Dehydration reaction of alcohols
180 degrees Celsius temperature Concentrated H2SO4 (dehydrating agent) products= alcohol into alkene + water
Primary alcohol
1 OH group attached to a C that is attached to only 1 other C
E.g ethanol
Secondary alcohol
Alcohol with 1OH group attached to a C attached to 2 other Cs
E.g propan-2-ol
Tertiary alcohol
Alcohol with 1OH group attached to a C attached to 3 other Cs
E.g 2-methylpropan-2-ol
How are alcohols oxidised?
Addition of acidified solution of potassium dichromate(VI)
Orange to green
Oxidation of primary alcohols
Aldehyde formed
Suffix = “-al”
Further oxidation of primary alcohols
Aldehyde further oxidised to form a carboxyllic acid
Oxidation of secondary alcohols
Forms a ketone
Suffix = “-one”
Why is there no further oxidation in secondary alcohols?
C=O bond is in middle
Oxidation of tertiary alcohols
No oxidation occurs as no C=O can be formed as another C is attached not a H so can’t be broken
K2Cr2O7 and heat observations with primary, secondary and tertiary alcohols
Primary and secondary = orange to green
Tertiary = no change (stays orange)
Add NaHCO3(aq) to a carboxyllic acid
Fizzing observed
