10B. Ethers

Question 1

Ethers

Answer 1

• compounds containing an oxygen atom bonded to two cabon atoms

C - O - C

• structurally ethers may be viewed as derivatives of water in which both hydrogen atoms have been replaced by alkyl groups, although the bond angle at the oxygen atom is a little larger than that of water - 110o

Question 2

Naming

Answer 2

• usually involves using common names
• each group attached to the oxygen is named + ordered alphabetically, followed by ‘ether’
• more complex ethers are named as alkoxyalkanes, alkoxyalkenes or alkoxyarenes where the RO- group is an alkoxy group
• cycloethers, where the oxygen is one of the atoms of the ring, are also known by their common names

Question 3

Physical Proprties

Answer 3

• although ethers are polar compounds in which oxygen has a partial negative charge + each attached carbon have partial positive charges, there are only weak forces of attraction between ether molecules in liquid form
• consequently the boiling points of ethers are similar to those of hydrocarbons of similar molecular weight
• ethers are more soluble in water than hydrocarbons of similar molecular weight + shape, but far less soluble than isomeric alcohols, as the oxygen atom of an ether forms hydrogen bonds with water

Question 4

Reactions

Answer 4

• ethers are generally inert substances - they are not oxidised or reduced, they are unaffected by most acids + bases - and because of their good solvent properties, they are used especially as solvents in which to carry out many organic reactions