Fajan Rule: Greater is the polarization, greater is the covalent character. | Online Chemistry tutorial IIT, CBSE Chemistry, ICSE Chemistry, engineering and. This lesson will talk about polarization of ionic compounds and Fajans’ rules. Fajans’ rules discuss introduction of covalent character in ionic. Inorganic Chemistry/Chemical Bonding/Fajan’s Rule. From Wikibooks, open books for an open world. < Inorganic Chemistry | Chemical Bonding. Unreviewed.

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Leave a Reply Cancel reply Your email address will not be published. Gas To Solid Is Called. Note that Fajans’ Rules have been largely displaced by Pauling’s approach using electronegtivites.

bond – What is Fajans rule? – Chemistry Stack Exchange

Chemistry Stack Exchange works best with JavaScript enabled. Take learning on the go with our mobile app. These compounds are molecular in nature and not ionic, their reactions are molecular and proceed at a much slower rate than those of ionic compounds.

Let us consider AlI 3 ; this is an ionic bond which was formed by transfer of electrons. Fajans’ rule states that a compound with low positive charge, large cation and small anion has ionic bond where as a compound with high positive charge, small cation and large anion are covalently bonded. Two contrasting examples can illustrate the variation in effects. Practise s of questions mapped to your syllabus.


Fajans’ Rule – Disclosing Covalent Characteristics in Ionic Bonds

The effect is called polarisation of the anion. This page was last edited on 18 Novemberat When a cation approaches an anion, the electron cloud of the anion is attracted towards a cation and hence gets distorted.

They are a method for predicting ionic vs. In reality, every bond has some covalent as well as ionic characteristics. Congratulations You have selected the correct answer!!

A cation having inert gas like configuration has less polarising power in comparison to cation having pseudo-inert gas like configuration. Hence covalent character increases.

Inorganic Chemistry/Chemical Bonding/Fajan’s Rule

However, the remnants of Fajans’ Rules are found in Hard-Soft Acid-Base Theorywhich predicts bonding properties based on polarizability which is based on size and charge. They can be summarized in the following table:.

Now, if we consider the iodine atom, we see that it is relatively large and thus the outer shell electrons are relatively well shielded from the nuclear charge. Fajans’ rules note the difference were formulated in by Kazimierz Fajans. Covalent character of lithium halides is cajan the order:. By Fajans’ Rules, compounds are more likely to be ionic if: They are generally soluble in organic solvents but insoluble in water and other polar solvents.

To use Fajans’ Rules, assume your binary compound is ionic and identify the potential cation and anion.

Fajan’s Rules | Chemical Bonding and Molecular Structure, Chemistry, Class 11

Login to track and save your performance. Where fajsn larger is the size of anion, more will be the polarization of anion.


You have selected the wrong answer!! Larger the charge on the cation, greater is its polarising power.

As the atoms in covalent compounds are held together by the shared electrons ,it is rigid eule directional. In inorganic chemistryFajans’ rulesformulated by Kazimierz Fajans in[1] [2] [3] are used to predict whether a chemical bond will be covalent or ionicand depend on the charge on the cation and the relative sizes of the cation and anion.

Practise This Question The acid formed when sulphur trioxide reacts with water is. If two cations have the same size and charge, then the one with 18 electrons in the outermost shell has greater polarising power than the other with 8 electrons in the outermost shell.

The crystal structure of covalent compounds differ from that of ionic compounds. In this article, we are going to discuss covalent characteristics in ionic bonds. What Is Valence Bond Theory. Views Read Edit View history. Because if this electron cloud of anion is more diffused.

Now, if we take a different example, for example AlF 3 Aluminium Fluoride.