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प्रश्न
Describe the general trends in the following properties of the elements in Groups 13 and 14.
Oxidation states
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उत्तर
Possible oxidation states Group 13 elements are from +3 to –5. But the stability of +1 oxidation state increases down the group due to inert their effect than the stability of +3 oxidation state.
Similarly, in group 14, The common oxidation states shown by the carbon family are +2 and +4. Due to the inert pair effect, stability of +2 oxidation state increases then the stability of +4.
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संबंधित प्रश्न
If B–Cl bond has a dipole moment, explain why BCl3 molecule has zero dipole moment.
Suggest reasons why the B–F bond lengths in BF3 (130 pm) and `"BF"_4^(-)` (143 pm) differ.
What happens when BF3 is reacted with ammonia?
Write a balanced equation for Al + NaOH → ?
Which of the following oxides is acidic in nature?
Dry ice is ______.
Which of the following statements are correct. Answer on the basis of Figure.
(i) The two birdged hydrogen atoms and the two boron atoms lie in one plane;
(ii) Out of six B – H bonds two bonds can be described in terms of 3 centre 2-electron bonds.
(iii) Out of six B – H bonds four B – H bonds can be described in terms of 3 centre 2 electron bonds;
(iv) The four-terminal B – H bonds are two centre-two electron regular bonds.
Explain why the following compounds behave as Lewis acids?
AlCl3
When BCl3 is treated with water, it hydrolyses and forms [B[OH]4]– only whereas AlCl3 in acidified aqueous solution forms [Al(H2O)6]3+ ion. Explain what is the hybridisation of boron and aluminium in these species?
Aluminium dissolves in mineral acids and aqueous alkalies and thus shows amphoteric character. A piece of aluminium foil is treated with dilute hydrochloric acid or dilute sodium hydroxide solution in a test tube and on bringing a burning matchstick near the mouth of the test tube, a pop sound indicates the evolution of hydrogen gas. The same activity when performed with concentrated nitric acid, reaction doesn’t proceed. Explain the reason.
Explain the following:
Boron does not exist as B3+ ion.
Explain the following:
Pb4+ acts as an oxidising agent but Sn2+ acts as a reducing agent.
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 |
Describe the general trends in the following properties of the elements in Groups 13 and 14.
Metallic character
Account for the following observations:
Though fluorine is more electronegative than chlorine yet BF3 is a weaker Lewis acid than BCl3
Account for the following observations:
PbO2 is a stronger oxidising agent than SnO2
Three pairs of compounds are given below. Identify that compound in each of the pairs which has group 13 element in more stable oxidation state. Give reason for your choice. State the nature of bonding also.
TlCl3, TlCl
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 ______.
