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
Carboxylic acid + Alcohol ==> ….
… Ester + Water
Acid anhydride + Alcohol ==> ….
… Ester + Carboxylic acid
What is a carboxylic acid?
it is a molecule with the formula R-COOH
What are some examples of derivatives of carboxylic acids?
Esters
Acid anhydrides
Name 3 different environments where an -OH can occur
As part of a carboxylic acid group
As part of a primary/secondary/tertiary alcohol
As part of a benzene ring (Phenol)
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 does a carboxylic acid react with a strong base like NaOH?
R-COOH + NaOH ==> R-COO-Na+ + H2O
How are organic liquids purified?
Using a separating funnel and using a drying agent and also using distillation
Carboxylic acid + Alcohol ==> ….
… Ester + Water
Acid anhydride + Alcohol ==> ….
… Ester + Carboxylic acid
What is a carboxylic acid?
it is a molecule with the formula R-COOH
What are some examples of derivatives of carboxylic acids?
Esters
Acid anhydrides
Name 3 different environments where an -OH can occur
As part of a carboxylic acid group
As part of a primary/secondary/tertiary alcohol
As part of a benzene ring (Phenol)
What is the order of acidity: Carboxylic acid Ethanol Phenol Water
Ethanol < Water < Phenol < Carboxylic Acid
Which can react with strong bases like NaOH: Carboxylic acid Ethanol Phenol Water
Phenols and Carboxylic acids can react with STRONG bases
How does a phenol react with a strong base like NaOH?
Phenol + NaOH ==> Sodium phenoxide + H2O
Sodium phenoxide is a benzene ring with a negative oxygen ion and a positive sodium ion on one of the carbons. C6H5O-Na+
What are the types of product formed from a reaction of either a Carboxylic acid or phenol when reacted with a strong base?
Water and a Salt
Which reacts with carbonates e.g. Na2CO3 and why? Carboxylic Acid Ethanol Phenol Water
Only carboxylic acids dissociate enough in solution (so produce a high enough concentration of H+ ions) to react with carbonates
CO3(2-) + 2H+ ==> CO2 + H2O
What is a test for phenol and its DERIVATIVES?
Neutral Iron(III) chloride forms a purple complex when reacted with phenols
How can an ester be made using a phenol?
It is reacted with a acid anhydride to form a ester and a carboxylic acid
Phenol + Acid anhydride ==> …
… Ester and Carboxylic acid
Do phenols react with carboxylic acids to produce esters?
NO
What is salicylic acid (What does it look like)?
It is a phenol with a carboxylic acid attatched
What is aspirin (What does it look like)?
It is a benzene ring with a carboxylic acid group and an ester with a methyl group attatched
HOOC - BENZENE - OCOCH3
How can salicylic acid be esterified?
The phenol group can be reacted with an acid anhydride
or
The carboxylic acid group can be reacted with an alcohol
How is salicylic acid be turned into Aspirin?
The phenol group can be reacted with an acid anhydride
Salicylic acid is reacted with an alcohol, what is the process? What is this called?
The carboxylic acid group on the salicylic acid becomes an ester group and what is produced is called oil of wintergreen.
What is oil of wintergreen?
It used as a linament (rubbed on the body to relieve pain)
It is soluble in fats rather than water so can be absorbed through the skin and it reduces pain and swelling
How does infrared spectroscopy work?
A substance is exposed to different frequencies of infrared radiation. The amount of radiation that is absorbed by the substance is then recorded and graphed.
What is the equation that relates wavelength and frequency?
c = fν
How do simple diatomic molecules vibrate? How many ways?
Only one way
The molecule stretches (the atoms pull apart and then push together)
Why do different molecules absorb different frequencies?
Because the different bonds within the molecule require different amounts of energy to vibrate
What are the possible ways that a CO2 molecule can vibrate?(3 ways)
Symmetric stretch - when the atoms in the CO2 pull apart. Each oxygen pulls in a different direction
asymmetric stretch - when the atoms in the CO2 stretch but in the same direction
Symmetric bend - This is when the molecule bends. The carbon moves in one direction and the oxygens go in the other direction
What is the fingerprint region?
Below 1500cm^-1, the spectrum becomes quite complex and it is harder to identify bonds. The formation of this area is often called the fingerprint region because it unique to a particular molecule
LEARN HOW TO READ IR SPECTROSCOPY
DO IT RIGHT NOW
What can mass spectrometry be used for?
It can be used to work out the atomic mass of elements and also the relative abundance of isotopes of the element. It can also be used to work out the mass of fragments of the molecule which can be used to identify the molecule
What is the M+ ion peak used for?
Helps chemists determine the mass of the molecule
LEARN HOW TO READ MASS SPECTROMETRY
PROBABLY WILL COME UP SO U SHOULD LEARN IT
What is green chemistry?
Developing chemical products using chemical processes that are sustainable and as environmentally friendly as possible
What are the principles of green chemistry? (12 principles)
- Better atom economy
- Prevention of waste products
- Less hazardous chemical synthesis
- Design safer chemical products
- Use safer solvents
- Lower energy usage
- Using renewable resources
- Reduce the number of steps and reactants required
- Use catalysts
- Design products that naturally degrade
- Employ real time process monitoring to reduce waste
- Use safer chemical prodcesses
What are 3 methods of purifying organic solids?
Recrystallisation
Thin layer chromatography
Melting point determination
What is the process of recrystallisation?
The product is dissolved in hot solvent (the solvent only dissolves the product when it is hot) and then all impurities can be filtered. Then as the solvent cools the product starts to recrystallise and become a solid. this can then be filtered out and collected. The solid crystals then need to be washed
What is the process for thin layer chromatography?
A line is drawn 1 cm from the bottom of a silica plate
The test sample and a reference sample is placed on the line
Then the silica plate is placed in the beaker filled with about 0.5cm deep solvent.
The solvent travels up the plate and before it reaches the top, it is taken out.
the reference sample and the test sample are compared
What is the process of melting point determination?
The melting point is measured and as long as the obtained value is close to the published value then it is pure
