Advertisements
Advertisements
प्रश्न
Describe the general trends in the following properties of the elements in Groups 13 and 14.
Metallic character
Advertisements
उत्तर
The metallic character in group 13 follows an unusual trend. Metallic character First increases from Boron to aluminium and then decreases from aluminium to thallium. This decrease is majorly due to the poor shielding effect of d and f electrons present in the heavier metals.
In group-14, as we move down the group, the metallic character increases.
APPEARS IN
संबंधित प्रश्न
How can you explain higher stability of BCl3 as compared to TlCl3?
If B–Cl bond has a dipole moment, explain why BCl3 molecule has zero dipole moment.
In some of the reactions thallium resembles aluminium, whereas in others it resembles with group I metals. Support this statement by giving some evidences.
Write a balanced equation for Al + NaOH → ?
Write a balanced equation for B2H6 + NH3 → ?
Ionisation enthalpy (∆iH1kJ mol–1) for the elements of Group 13 follows the order.
Explain the following:
Electron gain enthalpy of chlorine is more negative as compared to fluorine.
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:
Though fluorine is more electronegative than chlorine yet BF3 is a weaker Lewis acid than BCl3
Account for the following observations:
The +1 oxidation state of thallium is more stable than its +3 state.
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.
AlCl3 , AlCl
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.
Boron compounds behave as Lewis acids because of their ______.
Taking stability as the factor, which one of the following represents the correct relationship?
