Question

The +1 oxidation state in group 13 and +2 oxidation state in group 14 becomes more and more stable with increasing atomic number. Explain

Answer 1

Hi,

Here is your answer,

The term inert pair effect is often used in relation to the increasing stability of oxidation states that are 2 less than the group valency for the heavier elements of group 13, 14, 15 and 16.

In group 13 all the elements show +3 oxidation state whereas, Ga, In and Ti show +1 oxidation state also.

Boron, being small in size can lose its valence electrons to form B(to the power of 3+) ion and shows +3 oxidation state.

+1 oxidation state of Ti, Ga is due to inert pair effect. The outer shell s-electron (ns2) penetrate to (n-1) d-electrons and thus becomes closer to nucleus and are more effectively pulled towards the nucleus.

This result in less availability of ns2 electrons pair for bonding of ns2 electron pair becomes inert. This reluctance in the participation of ns2 electrons is bonding is termed as inert pair effect. The inert pair is more effective after n > 4 and Increases value of n.

Now, for group 14, in spite of 4 valence electrons, they do not form M( to the power of 4+) and Pb(to the power of 2+) show ionic nature. The tendency to from +2 ionic state increases on moving down the group due to inert pair effect.


Hope it helps you!

Answer 2

Hii

Here is your answer -

In group 13 and 14, as we move down the group, the tendency of s-electrons of the valence shell to participate in bond formation decreases. This is due to ineffective shielding of s-electrons of the valence shell by the intervening d- and f-electrons. This is called inert pair effect.

Due to this, s-electrons of the valence shell of group 13 and 14 are unable to participate in bonding. Hence, +1 and +2 oxidation states, in group 13 and 14 respectively, become -more stable with increasing atomic number.