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.
The general electronic configuration of group 14 elements is [Noble gas] ns2np2, so these elements are expected to show a uniform oxidation state of +4. Carbon and silicon show an oxidation state of +4 only, but tin and lead, however, show oxidation states of +2 and +4.
As we move down the group, the stability of +4 oxidation state decreases and that of+2 oxidation state increases. This means that as we move down the group, the tendency of the s- electron of the valence shell to precipitate in a bond formation decreases. In other words, the pair of s-electrons, 5s in tin and 6s in lead behaves as inert. This is called inert pair effect. Because of inert pair effect, only the np2 electron of tin and lead take part in bonding with the atoms of the other elements. Thus, divalent compounds of tin and lead are stable.
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.
