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प्रश्न
Explain the following:
Why does the element silicon, not form a graphite like structure whereas carbon does.
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उत्तर
In graphite, carbon is sp2-hybridised and each carbon is linked to three other carbon atoms by forming hexagonal rings. Each carbon is now left with one unhybridised p-orbital which undergoes sideways overlap to form three p-p double bonds. Thus, graphite has two-dimensional sheet like (layered) structure consisting of a number of benzene rings fused together. Silicon, on the other hand, does not form an analogue of carbon because of the following reason:
Due to bigger size and smaller electronegativity of Si than C, it does not undergo sp2-hybridisation and hence it does not form p-p double bonds needed for graphite like structure. Instead, it prefers to undergo only sp3-hybridisation and hence silicon has diamond like threedimensional network
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संबंधित प्रश्न
Discuss the pattern of variation in the oxidation states of C to Pb.
Rationalise the given statement and give a chemical reaction:
Lead (II) chloride reacts with Cl2 to give PbCl4.
Explain why is there a phenomenal decrease in ionisation enthalpy from carbon to silicon?
Elements of group 14 ________.
Classify the following oxide as neutral, acidic, basic or amphoteric:
B2O3
Classify the following oxide as neutral, acidic, basic or amphoteric:
PbO2
Classify the following oxide as neutral, acidic, basic or amphoteric:
Tl2O3
Write suitable chemical equations to show the nature of the following oxide.
SiO2
Write suitable chemical equations to show the nature of the following oxide.
CO2
Catenation i.e., linking of similar atoms depends on size and electronic configuration of atoms. The tendency of catenation in Group 14 elements follows the order:
The reason for small radius of Ga compared to Al is:
(i) poor screening effect of d and f orbitals.
(ii) increase in nuclear charge.
(iii) presence of higher orbitals.
(iv) higher atomic number.
The linear shape of CO2 is due to:
(i) sp3 hybridisation of carbon.
(ii) sp hybridisation of carbon.
(iii) pπ – pπ bonding between carbon and oxygen.
(iv) sp2 hybridisation of carbon.
Give reasons for the following:
CCl4 is immiscible in water, whereas SiCl4 is easily hydrolysed.
Explain the following:
Silicon forms \[\ce{SiF^{2-}6}\] ion whereas corresponding fluoro compound of carbon is not known.
Explain the following:
Silicon forms \[\ce{SiF^{2-}6}\] ion whereas corresponding fluoro compound of carbon is not known.
The +1 oxidation state in group 13 and +2 oxidation state in group 14 becomes more and more stable with increasing atomic number. Explain.
Explain the following:
BF3 does not hydrolyse.
Which one of the following compounds of Group–14 elements is not known?
Match List I with List II:
| List I | List II |
| Coke | Carbon atoms are sp3 hybridized. |
| Diamond | Used as a dry lubricant. |
| Fullerene | Used as a reducing agent. |
| Graphite | Cage like molecules |
Choose the correct answer from the options given below:
