Advertisements
Advertisements
Question
Ionisation enthalpy (∆iH1kJ mol–1) for the elements of Group 13 follows the order.
Options
B > Al > Ga > In > Tl
B < Al < Ga < In < Tl
B < Al > Ga < In > Tl
B > Al < Ga > In < Tl
Solution
B > Al < Ga > In < Tl
Explanation:
On moving down the group from B to Tl, a regular decreasing trend in the ionisation energy values is not observed.
| Element | B | Al | Ga | In | Tl |
| I.E. (kJ/mol) | 801 | 577 | 579 | 558 | 589 |
In Ga, there are ten d-electrons in the penultimate shell which screen the nuclear charge less effectively and thus, outer electron is held firmly. As a result, the ionisation energy of both A1 and Ga is nearly the same. The increase in ionisation energy from In to Tl is due to poor screening effect of 14f electrons present in the inner shell.
APPEARS IN
RELATED QUESTIONS
What do you understand by inert pair effect?
The geometry of a complex species can be understood from the knowledge of type of hybridisation of orbitals of central atom. The hybridisation of orbitals of central atom in [Be(OH)4]– and the geometry of the complex are respectively.
The most commonly used reducing agent is ______.
Explain why the following compounds behave as Lewis acids?
AlCl3
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.
Nature of halides
Account for the following observations:
Though fluorine is more electronegative than chlorine yet BF3 is a weaker Lewis acid than BCl3
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
Which one of the following is the correct statement?
