Alcohols Flashcards
Name the two industrial methods of making alcohols
Hydration of ethene, Fermenting glucose
What are the 3 conditions needed for the hydration of ethene
A phosphoric catalyst (H₃PO₄), 300°C, 60 atm
What are the two conditions needed for fermenting glucose
Yeast, 37°C.
How do you turn alkanes to alkenes to hydrate them
You have to crack the alkanes to get alkenes
Outline the method for fermenting glucose to make alcohol
All oxygen is used aerobically, then anaerobic respiration kicks in creating bubbles of CO₂.
Ethanol is toxic therefore killing all the yeast cells.
What is the percentage yield of fermenting glucose
10%
How do you improve the yield of fermenting glucose
Before all the glucose is used you distil the ethanol then add excess glucose to continue the reaction
What are the advantages of the hydration of ethene
100% atom economy, It’s a continuous process
What are the disadvantages of the hydration of ethene
-Hard to reach 300°C and 60 atm
-Burning crude oil (greenhouse gas CO₂)
-Not sustainable, non-renewable
What are the advantages of the fermentation of glucose
-Sustainable, renewable
-Carbon neutral (to a point)
What are the disadvantages of the fermentation of glucose
-lower atom economy
-Expensive
-batch process
-ethanol is toxic therefore breaking
what do you need to oxidise an alcohol
an oxidising agent [O] known as acified potassium dichromate (VI). also written as H⁺/K₂Cr₂O₇
What colour is acified potassium dichromate (VI)
It starts as orange is goes green when reduced
What are the products when oxidising a primary alcohol
You get an aldehyde, and when you oxidise the aldehyde you get a carboxylic acid, and H₂O
What are the products when a secondary alcohol is oxidised
a Ketone + H₂O
What are the products when oxidising a tertiary alcohol
Nothing, they cannot be oxidised
What is a tertiary alcohol
an alcohol where the carbon that’s connected to the (OH) functional group is also attached to 3 other carbons
If you want to get an aldehyde from a primary alcohol what practical do you have to carry out
A Distillation
What practical do you have to carry out to oxidise an aldehyde to a carboxylic acid
Reflux
What is the functional group present in alcohols?
-OH functional group known as the hydroxyl group.
What is the simplest alcohol and its uses?
Methanol is the simplest alcohol, used as a fuel and an important chemical feedstock.
What are some products that use methanol as a starting material?
Methanol is used in polymers, paints, solvents, insulation, adhesives, and many other useful products.
What is the second member of the alcohol homologous series?
Ethanol, primarily used in alcoholic drinks.
What is the first step in naming alcohols?
Count the number of carbons and name accordingly.
What prefixes are used for alcohols with more than one -OH group?
Use the prefixes di, tri, tetra.
What should you consider when naming alcohols?
Look at the name of the -OH and what carbon they are bonded to, and look for any branches.
What type of bond do alcohols have due to electronegativity differences?
Alcohols have a polar O-H bond.
What type of intermolecular forces are present in alcohols?
Stronger intermolecular forces due to hydrogen bonding, but London forces are weak like in alkanes.
How can alcohols be classified?
Alcohols can be classified as primary, secondary, or tertiary.
What defines a primary alcohol?
A primary alcohol has 2 hydrogens attached to the carbon atom with the functional group (except methanol).
What defines a secondary alcohol?
A secondary alcohol has 1 hydrogen attached to the carbon atom with the functional group.
