Question

(a) Explain any two physical properties of ionic compounds giving reason.

(b) List any two metals found in free state in earth's crust. Where are they locate in activity series ?

(c) Metals towards the top of the activity series can not be obtained from their compounds by reducing with carbon. Why ?

Answer 1

(a) Physical properites of ionic compounds :
(i) Ionic compounds are usually crystalline solids because their oppositely charged ions attract one another strongly and forms a regular crystal structure.
(ii) Ionic compounds have high melting and boiling points. The ionic compounds are made up of +ve and -ve ions. There is a strong electrostatic force of attraction between the oppositely charged ions, which requires a lot of heat energy to break, making the melting and boiling point of the ionic compounds very high.

(b) Gold and platinum metals are found in free state in the earth's crust. These metals are located at the bottom in the reactivity series.

(c) Metals towards the top of the activity series are highly reactive. The oxides of highly reactive metals are very stable and cannot be reduced by 'carbon' to obtain free metals because these metals have more affinity for oxygen than carbon.