question_answer

  Give   reasons   for   the   following observations (a) Ionic compounds in general have high melting and boiling points. (b) Highly reactive metals cannot be obtained from their oxides by heating them with carbon. (c) Copper vessels get a green coat when left exposed to air in the rainy season.

Answer:

                  (a) Due to the high electrostatic force of attraction between the oppositely charged ions, ionic compounds have high melting and boiling points. (b) Highly reactive metals have high affinity with oxygen. Therefore, their oxides cannot be reduced by carbon.                                     (1) (c) Copper reacts with air to form basic copper carbonate which is green in colour.