Aromatic Hydrocarbons Flashcards
Define an aliphatic compound
An organic compound that consists of open chains of carbon atoms and closed chain compounds (rings) that resemble them in chemical properties
Why were aromatic compounds given such a name?
Because some of the early compounds discovered had pleasant smells
Define an aromatic compound
A compound that contains a benzene ring structure on their molecules
What is the molecular formula for benzene?
C6H6
Is benzene saturated or unsaturated?
It is highly unsaturated
Since benzene was unsaturated what had scientist predicted about its reactive?
They had predicted it was highly reactive
Why had scientist predicted benzene was highly reactive?
Because of the presence of three double bonds
What did scientists actually discover about benzenes reactivity?
It is very unreactive
What did scientists discover about the bonds in benzene?
There bond lengths in benzene are intermediate between that of a single and a double bond
What is different about the electrons in benzene compared to other compounds?
The electrons are delocalised i.e. they are not localised between pairs of carbon atoms but free to move inside the hexagon
What effect do the delocalised electrons have on benzene?
Benzene is extra stable which accounts for its unreactivity with regard to addition reactions
How is the structural formula of benzene drawn?
It is represented by a hexagon with a circle inside of it
Other then benzene, what two aromatic hydrocarbons are studied as part of the leaving cert course?
Methylbenzene
Ethylbenzene
How is methylbenzene drawn?
It is drawn like benzene except one hydrogen is replaced with a methyl group
What is the traditional name for methylbenzene?
Toluene
What is the main use for toluene?
It is used in TNT
What does TNT stand for?
Trinitrotoluene
Why is benzene considered dangerous?
It is highly toxic and carcinogenic
What aromatic hydrocarbon is used in place of benzene in the laboratory?
Methylbenzene
What form does methylbenzene take at room temperature?
Liquid
What is methylbenzene insoluble in?
Water
What is methylbenzene soluble in?
Organic solvents
Name two organic solvents that methylbenzene dissolves in
Cyclohexane
Propanone
What is a good property of methylbenzene?
It is a good solvent and can dissolve iodine crystals unlike water
