Analysis And Organic Synthesis

Question 1

How is IR spectroscopy be used outside a lab?

Answer 1

1. Breathalysers - amount of ethanol vapour in drivers breath is found by measuring the intensity of the peak corresponding to the C-H bond in the IR spectrum. Chosen because not effected by any water-vapour in the breath
2. Monitoring pollutants - intensity of peaks corresponding to the C triple bond O & N=O bonds can be studied to monitor their levels

Question 2

How do you find the Mr from a mass spectrum?

Answer 2

Molecular ion peak (highest m/z) ignoring any M+1 peak

Question 3

How does reflux work?

Answer 3

Mixture heated in flask fitted with vertical Liebig condenser, this means the mixture can be continuously boiled and as the vapours evaporate into the condenser they condense and a recycled back into the flask giving then time to react

Question 4

What is redistillation? How does it work?

Answer 4

How mixtures that contain volatile liquids can be purified. When the liquid you want boils you place a flask at the open end of the condenser ready to collect your product. When the temperature changes put another flask at the end of the condenser because a different liquid is about to be delivered

Question 5

How do you separate a product that is soluble in water from any impurities that dissolve in water?

Answer 5

Mixture can be poured into a separating funnel, and water added. Funnel is shaken then allowed to settle. Organic layer normally less dense than aqueous layer, so should float on top. Most of the water-soluble impurities should have dissolved in the lower aqueous layer

Question 6

How do you remove trace amounts of water from the organic product?

Answer 6

Add an anhydrous salt e.g. MgSO4 or CaCl2. This is used as a drying agent, it binds to any water present to become hydrated. You can filter the mixture to remove to solid drying agent

Question 7

For an alkane, what is the functional group, prefix/suffix, properties & typical reactions?

Answer 7

Functional group: only C-C and C-H
Prefix/suffix: ane
Properties: non-polar, unreactive
Typical reactions: radical substitution

Question 8

For an alkene, what is the functional group, prefix/suffix, properties & typical reactions?

Answer 8

Functional group: C=C
Prefix/suffix: -ene
Properties: non-polar, electron-rich double bond
Typical reactions: electrophilic addition

Question 9

For an alcohol, what is the functional group, prefix/suffix, properties & typical reactions?

Answer 9

Functional group: C-OH
Prefix/suffix: -ol (or hydroxy-)
Properties: polar C-OH bond
Typical reactions: nucleophilic substitution, dehydration, elimination, oxidation

Question 10

For a haloalkane, what is the functional group, prefix/suffix, properties & typical reactions?

Answer 10

Functional group: C-X
Prefix/suffix: halo- (e.g. chloro-)
Properties: polar C-X bond
Typical reactions: nucleophilic substitution

Question 11

For ketones, what is the functional group, prefix/suffix, properties & typical reactions?

Answer 11

Functional group: C=O
Prefix/suffix: -one
Properties: Polar C=O bond
Typical reactions: -

Question 12

For an aldehyde, what is the functional group, prefix/suffix, properties & typical reactions?

Answer 12

Functional group: HC=O
Prefix/suffix: -al
Properties: polar C=O bond
Typical reactions: oxidation

Question 13

For a carboxylic acid, what is the functional group, prefix/suffix, properties & typical reactions?

Answer 13

Functional group: -COOH
Prefix/suffix: -oic acid
Properties: Electron deficient carbon centre
Typical reactions: -

Question 14

What is a synthetic route?

Answer 14

A step-by-step pathway of how to get from one organic compound to another, showing the reagents, catalysts and conditions needed, as well as any intermediate products