Three alcohols - ethanol, propanol and butanol are mixed and heated for a long time in a beaker. Which is the last one to evaporate?
Butanol
Ethanol - C2H5OH
Propanol - C3H7OH
Butanol - C4H9OH
The three alcohols form a homologous series. Molecular mass increases in any homologous series due to which a gradation of physical properties occurs. The boiling point is a physical property and so it increases in a homologous series. So the last one to evaporate will be butanol.