Question

The Valence of iron in $FeC{{l}_{3}}$ is..

Answer 1

- Hint: Valence of any compound or element is defined as its combining capacity or it can also be defined as the number of electrons an element can lose or gain to attain a stable noble configuration. The compound which is more electropositive or more electronegative can lose or gain electrons respectively.

Complete step-by-step solution -
- $FeC{{l}_{3}}$ is an ionic compound.
- In general ionic compounds are composed of metal and non-metal. The metal cation and non-metal anion are attracted to each other by.
- In order to gain stability according to octet rule one element will give up or accept electrons to fill their valence shell. In $FeC{{l}_{3}}$ chlorine has more electronegativity than iron so it attracts the pairs of electrons towards it.
-There are three chlorine atoms present in the molecule. Hence, its valence should be 3
Hence the valence of iron comes as 3.
Addition Information:
$FeC{{l}_{3}}$ is partially ionic and partially covalent. In general when metal is bonded to a non-metal, they are held together by ionic bond but this is not the sufficient condition, the more important condition is the electronegativity that must be greater than 1.7 to be sure that the bond is ionic if not like in your example 1.2 then the bond will be polar covalent bond which means that the electronegativity difference is not enough for the electrons to be lost by iron and gained by chlorine but they are shared and shifted toward the chlorine atom as it has the greater electronegativity.

Note: Remember that valence and oxidation state are different from each other. Oxidation state of any element can be a minus number but valence of a compound is always a positive number. Iron can also have valence of 2. Actually iron is more stable when its valence is 2 because in its outermost shell, it has only two electrons.