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प्रश्न
Describe the general trends in the following properties of the elements in Groups 13 and 14.
Atomic size
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उत्तर
Grp-13 The atomic size of the boron family follows the irregular trend. Generally, down the group the size increases but Gallium has a smaller atomic radius than Aluminium due to the poor shielding effect of 3d-orbitals.
Order: B < Ga < Al < In < Ti
Grp-14 The size of the carbon family is smaller than the modern family and as we move down the group the atomic size increases regularly. The increase in covalent radius from carbon to silicon is prominent while from Silicon to lead a small increase in covalent radius is observed; this is due to the presence of completely filled D and f-orbital in the heavier members.
Order: C < Si < Ge < Sn < Pb
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संबंधित प्रश्न
How can you explain higher stability of BCl3 as compared to TlCl3?
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Write a balanced equation for B2H6 + NH3 → ?
Dry ice is ______.
Explain why the following compounds behave as Lewis acids?
AlCl3
Explain the following:
Tl (NO3)3 acts as an oxidising agent.
Identify the compounds A, X and Z in the following reactions:
\[\ce{X ->[Δ][370 K] HBO2 ->[Δ][> 370 K] Z}\]
Complete the following chemical equations:
\[\ce{Z + 3 LiAlH4 -> X + 3LiF + 3AlF_3}\]
\[\ce{X + 6H2 -> Y + 6H2}\]
\[\ce{3X + 3O2 ->[Δ] B2O3 + 3H2O}\]
Match the species given in Column I with the properties mentioned in Column II.
| Column I | Column II |
| (i) \[\ce{BF^{-}4}\] | (a) Oxidation state of central atom is +4 |
| (ii) AICI3 | (b) Strong oxidising agent |
| (iii) SnO | (c) Lewis acid |
| (iv) PbO2 | (d) Can be further oxidised |
| (e) Tetrahedral shape |
Match the species given in Column I with properties given in Column II.
| Column I | Column II |
| (i) Diborane | (a) Used as a flux for soldering metals |
| (ii) Galluim | (b) Crystalline form of silica |
| (iii) Borax | (c) Banana bonds |
| (iv) Aluminosilicate | (d) Low melting, high boiling, useful for measuring high temperatures |
| (v) Quartz | (e) Used as catalyst in petrochemical industries |
Describe the general trends in the following properties of the elements in Groups 13 and 14.
Ionisation enthalpy
Account for the following observations:
The +1 oxidation state of thallium is more stable than its +3 state.
BCl3 exists as monomer whereas AlCl3 is dimerised through halogen bridging. Give reason. Explain the structure of the dimer of AlCl3 also.
Boron fluoride exists as BF3 but boron hydride doesn’t exist as BH3. Give reason. In which form does it exist? Explain its structure.
Boron compounds behave as Lewis acids because of their ______.
A group 13 element ‘X’ reacts with chlorine gas to produce a compound XCl3. XCl3 is electron deficient and easily reacts with NH3 to form \[\ce{Cl3X –> NH3}\] adduct; however, XCl3 does not dimerize X is ______.
