State $Fajans$ rules for the partial covalent character of ionic bonds.
(N/A) The smaller the size of the cation and the larger the size of the anion,the greater the covalent character of an ionic bond.
The greater the charge on the cation,the greater the covalent character of the ionic bond.
For cations of the same size and charge,the one with electronic configuration $(n-1)d^n s^0$,typical of transition metals,is more polarising than the one with a noble gas configuration,$ns^2 np^6$,typical of alkali and alkaline earth metal cations.
The cation polarises the anion,pulling the electronic charge toward itself and thereby increasing the electronic charge density between the two nuclei. This is precisely what happens in a covalent bond,i.e.,the build-up of electron charge density between the nuclei.
The polarising power of the cation,the polarizability of the anion,and the extent of distortion (polarisation) of the anion are the factors that determine the percent covalent character of the ionic bond.
The greater the charge on the cation,the greater the covalent character of the ionic bond.
For cations of the same size and charge,the one with electronic configuration $(n-1)d^n s^0$,typical of transition metals,is more polarising than the one with a noble gas configuration,$ns^2 np^6$,typical of alkali and alkaline earth metal cations.
The cation polarises the anion,pulling the electronic charge toward itself and thereby increasing the electronic charge density between the two nuclei. This is precisely what happens in a covalent bond,i.e.,the build-up of electron charge density between the nuclei.
The polarising power of the cation,the polarizability of the anion,and the extent of distortion (polarisation) of the anion are the factors that determine the percent covalent character of the ionic bond.
Explore More
Similar Questions
Covalency is favoured in which of the following cases?
Medium
View SolutionWhich is the correct order of covalent nature?
Difficult
View SolutionHow many of the following orders of covalent character are $TRUE$?
$(i)$ $LiF < LiCl < LiBr < LiI$ (Fajans' rule: covalent character increases with increasing size of anion)
$(ii)$ $CaCl_2 < FeCl_2 < FeCl_3$ (Fajans' rule: covalent character increases with increasing charge on cation)
$(iii)$ $Hg_2Cl_2 < HgCl_2$ (Fajans' rule: covalent character increases with increasing charge on cation)
$(iv)$ $ZnCl_2 < CdCl_2 < HgCl_2$ (Fajans' rule: covalent character increases with increasing polarizability of cation)
$(v)$ $CuCl < AgCl < AuCl$ (Fajans' rule: covalent character increases with increasing polarizability of cation)
$(vi)$ $AlN > Al_2O_3 > AlF_3$ (Fajans' rule: covalent character increases with increasing charge on anion)
$(vii)$ $CaF_2 < CaCl_2 < CaBr_2 < CaI_2$ (Fajans' rule: covalent character increases with increasing size of anion)
$(i)$ $LiF < LiCl < LiBr < LiI$ (Fajans' rule: covalent character increases with increasing size of anion)
$(ii)$ $CaCl_2 < FeCl_2 < FeCl_3$ (Fajans' rule: covalent character increases with increasing charge on cation)
$(iii)$ $Hg_2Cl_2 < HgCl_2$ (Fajans' rule: covalent character increases with increasing charge on cation)
$(iv)$ $ZnCl_2 < CdCl_2 < HgCl_2$ (Fajans' rule: covalent character increases with increasing polarizability of cation)
$(v)$ $CuCl < AgCl < AuCl$ (Fajans' rule: covalent character increases with increasing polarizability of cation)
$(vi)$ $AlN > Al_2O_3 > AlF_3$ (Fajans' rule: covalent character increases with increasing charge on anion)
$(vii)$ $CaF_2 < CaCl_2 < CaBr_2 < CaI_2$ (Fajans' rule: covalent character increases with increasing size of anion)
Difficult
View SolutionThe melting points of $(i)$ $BeCl_2$, $(ii)$ $CaCl_2$, and $(iii)$ $HgCl_2$ follow the order:
MediumWBJEE 2019
View Solution$A$ metal,$M$,forms chlorides in its $+2$ and $+4$ oxidation states. Which of the following statements about these chlorides is correct?
MediumAIEEE 2006
View SolutionVedclass Products
For Students
Vedclass Test Series
Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.
Start Free TrialFor Teachers
Exam Paper Generator
Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.
Try FreeFor Institutes
Online Exam Module
Live online exams with unlimited students, 360° analytics & white-label branding.
See Demo