Question

Fajan rule in nacl and cucl I didn't understand even after seeing the video...

Answer 1

The rule can be stated on the basis of 3 factors, which are:

1. Size of the ion: Smaller the size of cation, larger the size of the anion, greater is the covalent character of the ionic bond.
2. Charge of Cation: Greater the charge of cation, greater is the covalent character of the ionic bond.
3. Electronic configuration: For cations with same charge and size, the one, with (n-1)dⁿ ns^o which is found in transition elements have greater covalent character than the cation with ns² np⁶ electronic configuration, which is commonly found in alkali or alkaline earth metals

-CuCl is more covalent than NaCl because Cu has same size as that of Na & CuCl has pseudonobal gas configration due to which it has 18 electrons in outermost shell than Na Cl which has 8 elctrons.

( ie according to 3rd factor mentioned above)