phenols is involved in intermolecular hydrogen bonding as shown below: It is interesting to note that boiling points of alcohols and phenols are higher in comparison to other classes of compounds, namely hydrocarbons, ethers, haloalkanes and haloarenes of comparable molecular masses. For example, ethanol and propane have comparable molecular masses but their boiling points differ widely. The boiling point of methoxymethane is intermediate of the two boiling points. .
. Physical Properties . Show how are the following alcohols prepared by the reaction of a suitable Grignard reagent on methanal ? .
Write structures of the products of the following reactions: (iii) (i) The high boiling points of alcohols are mainly due to the presence of intermolecular hydrogen bonding in them which is lacking in ethers and hydrocarbons. Solubility Solubility of alcohols and phenols in water is due to their ability to form hydrogen bonds with water molecules as shown. The solubility decreases with increase in size of alkyl/aryl (hydro- phobic) groups. Several of the lower molecular mass alcohols are miscible with water in all proportions.
Arrange the following sets of compounds in order of their increasing boiling points: (a) Pentan- -ol, butan- -ol, butan- -ol, ethanol, propan- -ol, methanol. (b) Pentan- -ol, n-butane, pentanal, ethoxyethane. (a) Methanol, ethanol, propan- -ol, butan- -ol, butan- -ol, pentan- -ol. (b) n-Butane, ethoxyethane, pentanal and pentan- -ol.