question_answer 20)

How can ethanol and ethanoic acid be differentiated on the basis of their physical and chemical properties ? 

Answer:

Distinction based on physical properties. (i)Smell : Ethanol has a characteristic smell known as alcoholic smell which is pleasant. Ethanoic acid has vinegar like smell. (ii) Boiling points : Boiling point of ethanol (351 K) is less than that of ethanoic acid (391 K). (iii) Litmus test: Ethanol is neutral in nature and does not bring any change in the colour of litmus whether blue or red. Ethanoic acid is acidic and changes the colour of a blue litmus strip to red when dipped in it. Distinction based on chemical properties: (i) Action with sodium hydrogen carbonate: On adding a small amount of sodium hydrogen carbonate to ethanoic acid, carbon dioxide gas is evolved with brisk effervescence. However, no such reaction is noticed in case of ethanol.   (ii) Action with caustic alkalies : Ethanoic reacts with both sodium hydroxide (NaOH) and potassium hydroxide (KOH) to form corresponding salt and water. Ethanol fails to react with either of these.