Advertisements
Advertisements
प्रश्न
Describe the general trends in the following properties of the elements in Groups 13 and 14.
Nature of halides
Advertisements
उत्तर
Except thallium, All the elements of the boron family combine with three atoms of halogens to form trihalides. All these halides exist as molecular species with hybridisation of sp2. All the trihalides are Lewis acid and their acidic strength of trihalides of boron is in order: Bf3 < BCl3 < BBr3 < Bl3. In group-14, except carbon, all group 14 elements on reaction with halogens form tetra halides where central metal atom shows the sp3 hybridisation state and corresponding tetrahedral shape.
There are few exceptions also, SnF4 and Pf4 are ionic in nature, while the rest are covalent compounds.
APPEARS IN
संबंधित प्रश्न
Aluminium trifluoride is insoluble in anhydrous HF but dissolves on the addition of NaF. Aluminium trifluoride precipitates out of the resulting solution when gaseous BF3 is bubbled through. Give reasons.
In some of the reactions thallium resembles aluminium, whereas in others it resembles with group I metals. Support this statement by giving some evidences.
Ionisation enthalpy (∆iH1kJ mol–1) for the elements of Group 13 follows the order.
In the structure of diborane ______.
The most commonly used reducing agent is ______.
Dry ice is ______.
Cement, the important building material is a mixture of oxides of several elements. Besides calcium, iron and sulphur, oxides of elements of which of the group (s) are present in the mixture?
Explain why the following compounds behave as Lewis acids?
AlCl3
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:
Pb4+ acts as an oxidising agent but Sn2+ acts as a reducing agent.
Explain the following:
Tl (NO3)3 acts as an oxidising agent.
Match the species given in Column I with the hybridisation given in Column II.
| Column I | Column II |
| (i) Boron in [B(OH)4]– | (a) sp2 |
| (ii) Aluminium in [Al(H2O)6]3+ | (b) sp3 |
| (iii) Boron in B2H6 | (c) sp3d2 |
| (iv) Carbon in Buckminsterfullerene | |
| (v) Silicon in \[\ce{SiO^{4-}4}\] | |
| (vi) Germanium in [GeCl6]2– |
Describe the general trends in the following properties of the elements in Groups 13 and 14.
Oxidation states
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.
InCl3, InCl
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.
A nonmetallic element of group 13, used in making bullet proof vests is extremely hard solid of black colour. It can exist in many allotropic forms and has unusually high melting point. Its trifluoride acts as Lewis acid towards ammonia. The element exihibits maximum covalency of four. Identify the element and write the reaction of its trifluoride with ammonia. Explain why does the trifluoride act as a Lewis acid.
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 ______.
Which one of the following is the correct statement?
