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.
Why silicon does not form an analogue of graphite?
Or
Why elemental silicon does not form graphite like structure as carbon does?
In graphite, carbon is sp2 hybridised and each carbon is thus linked to three other carbon atoms forming hexagonal rings and also it involves the formation of pi-pi double bonds. On the other hand, the size of a silicon atom is larger than carbon and hence silicon has no tendency to undergo sp2 or sp hybridization to form multiple bonds between themselves or with other atoms such as oxygen, nitrogen (for example Si = 0, Si = N). Therefore, silicon always undergoes sp2 hybridization and hence all the silicon compounds have tetrahedral geometry. Also, silicon has a lesser tendency for catenation than carbon because Si – Si bonds are much weaker than C – C bonds.
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.
