question_answer 74)

  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:

  In group 13, as we move down the group, the stability of+3 state decreases while that of +1 state progressively increases. The reason why the liability of +1 state increases down the group, is that the tendency of s-electrons of the valence shell to participate in bond formation decreases. This reluctance is called inert pair effect. This is due to ineffective shielding of\[n{{s}^{2}}\] -electrons of the valence shell by intervening d- and f-electrons. Similarly, in the group 14, the stability of +2 oxidation state increases as we go down in the group. This is also due to inert pair effect and reluctance of \[n{{s}^{2}}\] -electron to participate in bond formation on account of ineffective shielding of \[n{{s}^{2}}\] -electrons by intervening d- and f-electrons.