Short Answer TypeDefine catenation. How will you explain the tendency for catenation decreases in the order C > Si > Ge > Sn > Pb?
Explain inert pair effect with reference to carbon family.
Or
Explain C and Si are tetravalent, but Ge, Sn and Pb show divalent.
Discuss the pattern of variation in the oxidation state of C to Pb.
C and Si do not exhibit inert pair effect due to the absence of d-or f-electrons. As a result, they show an oxidation state of +4 only due to the presence of two electrons in the s-and two electrons in the p-orbital of the valence shell.
On the other hand, the elements from Ge to Pb contain the only d- and f-electrons and hence show oxidation state of +2 and +4 due to inert pair effect. Further, as we move down the group, the number of d-and f -electrons increases and consequently the inert pair effect becomes more and more pronounced. In other words ns2 electron pair in Ge, Sn and Pb tends to remain paired, thus stability of +2 oxidation state increases while that of +4 oxidation state decreases. Thus +2 oxidation state of Pb is more stable than its +4 oxidation state.
Why silicon does not form an analogue of graphite?
Or
Why elemental silicon does not form graphite like structure as carbon does?
Select the member of group 14 that:
(i) forms the most acidic dioxide
(ii) is commonly found in +2 oxidation state
(iii) is used as semiconductor.
Give the name of allotrope of carbon which:
(i) is the hardest substance known
(ii) is used by artists in pencils
(iii) has the property of adsorbing gases
(iv) is used for making electrodes
(v) is used for absorbing organic colouring matter.
(vi) is used in the manufacturing of boot polishes.
Switch
are known to exist. Give possible reason.
