Answer:
(a)
(i) Ionic compounds have strong force of attraction between the oppositely
charged ions (e.g., Na+ and ),
so they are solids.
Covalent compounds have weak force of attraction between their molecules,
so they are usually liquids or gases.
(ii)Ionic compounds are soluble in water but covalent
compounds are insoluble in water.
(iii) Ionic compounds conduct electricity when dissolved
in water or when melted because they contain ions (charged particles). But covalent
compounds like glucose do not conduct electricity because they do not contain
ions. (3)
(b) (i) The metal M which is in the middle of the reactivity
series (such as iron, zinc, lead, copper, etc.) is moderately reactive. Thus,
to obtain such metals from their compounds, their sulphides and carbonates (in
which they are present in nature) are first converted into their oxides by the
process of roasting and calcination respectively,
The metal oxides (MO) are then reduced to the
corresponding metals by using suitable reducing agents such as
carbon.
For example, zinc metal can be obtained from its oxide as
follow
(ii) The metal N which is high up in the reactivity series
(such as sodium, magnesium, calcium, aluminium, etc), is very reactive and
cannot be obtained from its compound by heating with carbon.
Therefore, such metals are obtained by electrolytic
reduction of their molten salt.
For example, sodium is obtained by the electrolysis of
molten sodium chloride (NaCl).
At cathode
At anode (2)
You need to login to perform this action.
You will be redirected in
3 sec