Lower members of ethers are gases while higher members are volatile with pleasant smell. The C-O bond in ethers are polar. They are nonlinear (angular) molecules with C-O-C bond angle of about 1100. Therefore, ethers are polar compounds and have a net dipole moment. For example, dipole moment of dimethyl ether is 1.3D.
Ethers are isomeric with alcohols. But they do not show hydrogen bonding and association because of their low polarity. The weak polarity of ethers do not appreciably affect their boiling points which are comparable to those of alkanes of comparable molecular mass but are much lower than the boiling points of isomeric alcohols.
Ethers containing upto 3 carbon atoms are soluble in water due to their hydrogen bond formation with water molecules.
The increase in the size of the alkyl group decreases the polar nature of C-O bond and hence it decreases the hydrogen bonding with water. As a result solubility of ethers decreases with increase in the number of carbon atoms. Ethers are soluble in hydrocarbons and other non-polar solvents like benzene.
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