PHYSICAL PROPERTIES OF ALCOHOL

1. State: The lower member of alcohols are usually colourless liquids whereas higher members are usually colourless and odourless solids.

2.Solubility: Alcohols are soluble in water. This is due to the hydroxyl group in the alcohol, which is able to form hydrogen bonds with water molecules and their decline solubility is due to the increase in their molecular  masses.

3. Boiling point and melting point : The boiling points of alcohols are much higher than those of alkanes with similar molecular weights. For example, ethanol, with a molecular weight (MW) of 46, has a boiling point of 78 °C (173 °F), whereas propane (MW 44) has a boiling point of −42 °C (−44 °F).

Boiling poits of isomeric one decreases with branching of hydrocarbon chain  du to decrease in their surface area of the molecules causing decree in van der waals  force of attraction.

4. Formation of solid addition compounds:  Lower members of alcohols like CH3OH can form solid addition compounds  which are called alcoholates viz. MGCL2.6C2H5OH

Leave a Comment