Question

i am really confused about the degree of melting and boiling point and electric conductivity of the chlorides of group 1A

Answer 1

Answer:

Always remember that covalent compounds have lower boiling and higher points and electrical conductivity than the ionic compounds.

Which implies, that if we can obtain the order of degree of covalency of each of the chlorides of 1st group then we can state the trend for melting and boiling points too !

And, we know that we can state the degree of covalency for Compounds of same group having one common ion by Fazan's Rule, so according to Fazan's Rule as we go down the group and as the size of cation increases that is from Lithium to Cesium, then degree of covalency of their chlorides decreases implying that Lithium Chloride will be the most covalent among all and so on the degree of covalency will decrease.

And hence we can straight away say, that all the three melting and boiling points and electrical conductivity will go on increasing as we go down the group as the ionic character increases on going down the group in group IA.

Fortunately enough , there happen to be no exceptions here !

Hope this helps you ! ｡◕‿◕｡