Melting and boiling points of ionic compounds are high.

Question

Account for the following: 

(i) Melting and boiling points of ionic compounds are high. 

(ii) Aluminium is more active than iron, yet there is less corrosion of aluminium when both are exposed to air. 

(iii) Solder is used for welding electrical wires together. (iv) A sulphide ore is converted into its oxide to extract the metal. 

(v) Tarnished copper vessels are cleaned with tamarind juice.

Answer 1

(i) Large amount of heatenergy is required to break the inter-ionic attractive forces. 

(ii) A thin but strong layer of aluminium oxide is formed on its surface which protects aluminium atoms underneath.

 (iii) Solder has a low melting point. 

(iv) It is easier to extract a metal from its oxide by the process of reduction than from its sulphide. 

(v) Tamarind juice is acidic and neutralizes the basic layer of copper carbonate on tarnished copper vessels.