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प्रश्न
Explain why is there a phenomenal decrease in ionisation enthalpy from carbon to silicon?
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उत्तर
Ionisation enthalpy of carbon (the first element of group 14) is very high (1086 kJ/mol). This is expected owing to its small size. However, on moving down the group to silicon, there is a sharp decrease in the enthalpy (786 kJ). This is because of an appreciable increase in the atomic sizes of elements on moving down the group.
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.
Rationalise the given statement and give a chemical reaction:
Lead (IV) chloride is highly unstable towards heat.
Rationalise the given statement and give a chemical reaction:
Lead is known not to form an iodide, PbI4.
Classify the following oxide as neutral, acidic, basic or amphoteric:
CO2
Classify the following oxide as neutral, acidic, basic or amphoteric:
Al2O3
Write suitable chemical equations to show the nature of the following oxide.
Al2O3
Which of the following is a Lewis acid?
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.
Give reasons for the following:
CCl4 is immiscible in water, whereas SiCl4 is easily hydrolysed.
Explain the following:
CO2 is a gas whereas SiO2 is a solid.
Carbon and silicon both belong to the group 14, but inspite of the stoichiometric similarity, the dioxides, (i.e., carbon dioxide and silicon dioxide), differ in their structures. Comment.
Explain the following:
Carbon shows catenation property but lead does not.
Explain the following:
BF3 does not hydrolyse.
The principal ore of lead is ______.
\[\ce{SiCl4 ->[H2O] (A) ->[\Delta] (B) ->[Na2CO3][heat] (C)}\]. The Compound C is ______.
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:
