Physical properties of ether

Physical properties of ether

Physical state and odour:- Dimethyl ether and ethyl methyl ether are gases at ordinary temperature while other members are colourless liquids having a characteristics ether smell.

Volatality :-  Lower ethers are highly volatile and are inflammable.

Density :-  They are lighter than water .

Solubility :- lower ethers (uptoC³) are soluble in water because of dipolar nature of the C-O bond which forms H - bonding with water. However solubility of ether in water decrease due to increase of size of nonpolar Alkyl or Aryl groups 

Boiling point:- Due to weak dipole - dipole  interaction among ether molecules , they show slightly higher b.pt than the corresponding n - alkanes having comparable molecular masses . For example b.pt on Dimethyl ether (CH3- O -CH3) is 248k while propane (CH3 - CH2 - CH3) is 231k.

However the boiling point of higher ether (>C⁴), are slightly lower than the corresponding n - alkanes of comparable molecular masses . For example , the boiling point of Diethyl ether (C2 H5 - O - C2H5 ) is 307 .6k while n-pentane is 309 .1K . The reason of decreasing boiling point may be due to the presence of O - atom which makes

the ether molecule less symmetrical as compared to n - alkane . As a result , the van der waals forces of attraction become less symmetrical ether than in n - alkanes of comparable molecular masses .

In comparison to alcohol , ether have much lower boiling points than the corresponding isomeric alcohols of comparable  molecular mass . It is because of absence of intermolecular H- bonding  in ether, which is formed in alcohols .

   For example boiling point of methyl phenyl

ether (C6 H5 O- CH3) is 423k while that of benzyl alcohol (C6 H5 CH2 OH) is 478k although both have same mol.mass (108).