Paper 2

Question 1

Homologous series

Answer 1

A series of organic compounds having the same functional group but with each successive member differing by CH2.

Question 2

Functional group

Answer 2

A group of atoms responsible for the characteristic reactions of a compound.

Question 3

Aliphatic

Answer 3

A compound containing carbon and hydrogen atoms joined together in straight chains, branched chains or non-aromatic rings.

Question 4

Alicyclic

Answer 4

An aliphatic compound arranged in non-aromatic rings with or without side chains.

Question 5

Aromatic

Answer 5

A compound containing a benzene ring.

Question 6

Structural isomers

Answer 6

Compounds with the same molecular formula but different structural formulae.

Question 7

Homolytic fission

Answer 7

Each bonding atom receiving one electron from the bonded pair, forming two radicals.

Question 8

Heterolytic fission

Answer 8

One bonding atom receiving both electrons from the bonded pair.

Question 9

Radical

Answer 9

A species with an unpaired electron.

Question 10

Stereoisomers

Answer 10

Compounds with the same structural formula but with a different arrangement in space.

Question 11

E/Z isomerism

Answer 11

An example of stereoisomerism in terms of restricted rotation about a double bond and the requirement for two different groups to be attached to each carbon atom of the C=C.

Question 12

cis-trans isomerism

Answer 12

A special case of E/Z isomerism in which two of the substituent groups attached to each carbon atom of the C=C group are the same.

Question 13

Electrophile

Answer 13

An electron pair acceptor.

Question 14

Nucleophile

Answer 14

An electron pair donor.

Question 15

What shape does the bonds around each carbon atom in an alkane form?

Answer 15

Each carbon atom has 4 bonding pairs of electrons. They all repel each other equally. So the molecule forms a tetrahedral shape around each carbon and each bond angle is 109.5 degrees.

Question 16

What does the boiling point of an alkane depend on?

Answer 16

Between the molecules there are induced dipole-dipole interactions (London forces) which hold them all together. The longer the carbon chain, the stronger the London forces. This is because there’s more surface contact and more electrons to interact. As the molecules get longer it takes more energy to overcome the London forces and the boiling point rises. A branched-chain alkane has a lower boiling point that its straight-chain isomer. Branched-chain alkanes can’t pack closely together and they have smaller molecular surface areas - so the London forces are reduced.