Whats in medicine Flashcards
What sort of bonds form between alcohol molecules? where does the bond form?
Hydrogen bonds
Between the Hydrogen and Oxygen on separate molecules
Why do hydrogen bonds form between alcohols?
Because the hydrogen is ∂+ and the oxygen is ∂- because it has spare electron pairs in its outer shell. This causes the molecules to be attracted to each other
What is a primary alcohol?
The OH- is bonded to a carbon which is bonded to just one other carbon
What is a secondary alcohol?
The OH- is bonded to a carbon which is bonded to 2 other carbon atoms
What is a tertiary alcohol?
The OH- is bonded to a carbon which is bonded to 3 other carbon atoms
What is the reagent in the oxidisation of an alcohol?
acidified potassium dichromate (K2Cr2O7)
How does acidified potassium dichromate become reduced?
The Cr2O7 ion becomes Cr2O7 2-.
The chromate goes from chromate 6+ to chromate 3+
What are the products of partial oxidisation of a primary alcohol? What are the conditions?
The product is an aldehyde.
The conditions are distillation with the alcohol in excess. So there is more alcohol than oxidising agent
What is the product of full oxidisation of a primary alcohol? What are the conditions?
The product is a carboxylic acid
The conditions are reflux with the oxidising agent in excess. So there is more oxidising agent than alcohol
How can a secondary alcohol be oxidised?
It can only be oxidised to a ketone
What is the product of the oxidisation of a secondary alcohol? What are the conditions?
The product is a ketone
The conditions are reflux with an oxidising agent
How can a tertiary alcohol be oxidised?
It cant
Why can a secondary alcohol not be oxidised further from a ketone?
It would involve breaking a covalent C-C bond
Why don’t tertiary alcohols oxidise?
Because the carbon with the OH- on does not also have a hydrogen atom bonded
What is the colour change of the oxidising agent, acidified potassium dichromate?
It goes from orange to green
What is refluxing?
This is a safe method of heating a volitile / flammable liquid. The liquid is placed in a pear shaped flask and a condenser is placed above. Anti-bumping granules are added and then a bunsen burner boils the liquid.
What do both aldehydes and ketones contain?
A carbonyl C=O
What is the dehydration of an alcohol?
This is the removal of water from an alcohol. The products are an alkene and water
What are the conditions required for the dehydration of an alcohol?
Heated alumina (Al2O3) at 300ºC or reflux with concentrated sulfuric acid
What type of reaction is a dehydration reaction?
It is an elimination reaction
What is an elimination reaction?
This is when a molecule is removed from a larger molecule
How can alcohol undergo a nucleophilic substitution with a halide ion?
The alcohol is reacted with a hydrogen halide. the halide ion attacks the OH- and substitutes it and then the H+ ion reacts with the OH- to form water
What are the two methods of forming an ester?
Using esterification or using an acid anhydride
What is the process of esterification?
An alcohol is reacted with a carboxylic acid to produce and ester and water.
Alcohol + Carboxylic acid ==> Ester + water
What are the conditions and catalyst used for esterification and why?
The reaction is very slow so a strong acid catalyst is present and the reaction happens under reflux. The ester then has to be separated from the mixture using distillation and purification
What is the process of using an acid anhydride to form an ester?
An acid anhydride is reacted with an alcohol to form an ester and a carboxylic acid
Acid anhydride + Alcohol ==> Ester + Carboxylic acid
Which is more reactive? A carboxylic acid or acid anhydride?
Acid anhydride
What is an ether?
It is molecule with an oxygen substituted into the carbon chain. They have the same formula as an alcohol but are very different.
Ether: R-O-R
How is an ether named?
The longer hydrocarbon chain is the parent and the smaller one comes later
How are organic liquids purified?
Using a separating funnel and using a drying agent and also using distillation