Chapter 15 - Alcohols Flashcards
What are Alcohols?
What is the general formula for Alcohols?
Note on their reactivity
They have the functional group -OH on a hydrocarbon
CnH2n+1OH
Relatively Reactive
When do you name Alcohols with a suffix only?
when do you name Alcohols with a prefix included?
When its the only functional group
When theres other functional groups you add the prefix ‘Hydroxy’
What are Primary Alcohols?
What are Secondary Alcohols?
What are Tertiary Alcohols?
OH group has 1 -Alkyl group attached to the C-OH
OH group has 2 -Alkyl groups attached to the C-OH
OH group has 3 -Alkyl groups attached to the C-OH
What are the physical properties of Alcohols?
- High Melting and Boiling Point
- -OH can hydrogen bond with water
- Longer Chain Alcohols are insoluble
- Shorter Chain Alcohols are soluble
Can can Alcohols be produced?
Hydration or Fermentation
What is Hydration?
What are the Conditions needed?
\What is the chemical formula for Hydration?
Hydration is adding water to an Alkene in presence of an acid catalyst (H3PO4 or H2S04)
Acid catalyst, aq conditions, 300 degrees temperature and 70 atm Pa
C2H4 + H2O —(H3PO4)—> C2H5OH
What are 3 advantages to Hydration?
What are 3 disadvantages to Hydration?
Continuous Reaction, forms a purer product, Higher % yield
Non-Renewable, Expensive, Extreme Conditions needed
What is Fermentation?
What are the conditions for fermentation?
What is the chemical formula for fermentation?
Using carbs to create sugars during anaerobic respiration and converting into alcohol by enzymes and yeast
Yeast, 30 - 40 degrees, Oxygen free environment
C6H12O6 > 2(C2H5OH) + 2(CO2)
At what % does the alcohol in the fermentation solution need to be in order for the process to stop?
15% alcohol, where enzymes are no longer able to function
How may impure Alcohols be separated by the fermenting solution?
Via fractional distillation, e.g. heating ethanol at its boiling point (78 degrees)
What are the advantages to fermentation?
What are the disadvantages to fermentation?
Sugar is Renewable and its cheap
What are the advantages to fermentation?
What are the disadvantages to fermentation?
Sugar is Renewable, cheap, ethanol made from fermentation is carbon neutral
Batch Process (not continuous like hydration), Alcohols need distilling to become pure, Lower % yield
How does ethanol created by fermentation different to ethanol made by hydration?
Its a biofuel and is carbon neutral, and its reactants are renewable
What dehydrogenation?
What is needed to dehydrate an Alcohol?
Elimination Reaction of Alcohols which removes -OH and H from it to form an Alkene
Hot excess H3PO4/H2SO4 or passing its vapors over AL2O3 at 600K
What do Primary Alcohols oxide into?
Aldehyde then possible Carboxylic Acid
