Organic 6: Bonding in Benzene and Steam Distillatio of Clove Oil with Solvent extraction experiment

describe the bonding in benzene

benzene’s formula is C6H6 → highly unsaturated

• 6Cs arranged in a ring, with each having 4 e-s in its outer shell

• 3 of these e-s form sigma bonds

• 2 signma bonds are formed b/n each carbon atom and the two carbon atoms at either side of it

• 3rd sigma formed b/n carbon atom and hydrogen atom

• thís forms the skeleton of the molecule giving a planar hexagonal ring

• each carbon atom now has one unused electron that is found in a p orbital that is at right angles to the planar molecule.

• The lobes of these p orbitals fuse sideways to form a single ring of charge above and below the sigma bonded skeleton. These are pi bonds.

• Within these pi bonds, the electrons are free to move around the entire ring and so are said to be ‘delocalised’.

• It is this delocalisation that causes all the carbon- carbon bonds in benzene to be similar, and makes the molecule unexpectedly stable.

so the carbon-carbon bonds in benzene are intermediate between the two; therefore benzene undergoes substitution reactions typically, but not addition

 

important facts about benzene

1. Benzene is a planar molecule hence is non-polar as the centres of positive and negative charges coincide.

2. Benzene is insoluble in water as it is non-polar and does not form hydrogen bonds with water but is soluble in non-polar solvents such as cyclohexane.

3. It used to be used, as an organic solvent but is no longer due to the highly carcinogenic nature of the substance. Methylbenzene (toluene) is now used as a substitute for it as it is a good solvent.

principle of steam distillation

when two immiscible liquids are together, their boiling point is lower than either of the two pure compounds alone

emulsion

when two immiscible liquids are together and one is dispersed through the other as tiny droplets