Question

Account for the following:
a) Melting and boiling point of ionic compounds are high.
b) Aluminum is more reactive than iron, yet there is less erosion of aluminum when both are exposed to air.
c) Tarnished copper vessels are cleaned with tarmarind juice.​

Answer 1

Answer:

a) It is so because of the strong inter-ionic force of attraction between the positively and negatively charged elements .

b)It is so because Aluminium forms a protective layer of Aluminum oxide (Al + O2 -Al2O3)

c)It is so because tamarind juice is acidic in nature and hence remove the dull layer of copper.

Hope it will help...

Answer 2

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REASONS :

A) The ionic compounds have strong electrostatic forces of attraction between the oppositely charged ions. Therefore, large amount of energy is needed to break these bonds and hence there melting and boiling point are high.

B) When aluminum is exposed to air thin, a thin layer of aluminum oxide is formed on its surface. This protects the aluminum atoms underneath and therefore, there is less erosion of aluminum when exposed to air.

C) Tarmarind juice is acidic and it neutralises the basic layer of copper carbonate on tarnished copper vessels. Therefore, tarnished copper vessels are cleaned with tarmarind juice.