write the significance and limitations of octet rule
Answers
The octet rule successfully explains the formation of chemical bonds depending upon the nature of the element.
It is used to determine stability in atoms.
The octet rule helps to figure out how atoms will bond with one another.
limitations of octet rule are:
Some limitations of the octet rule are: It cannot be applied to the nonmetals after silicon in the periodic table. These elements can “expand their octet” and have more than eight valence electrons around the central atom. Examples are PF₅ , SF₆ and H2SO4 . Helpful 1 Confusing 1 Molecules with an odd number of electrons such as NO and NO₂ cannot satisfy the octet rule. At least one atom must have an odd number of electrons. In some molecules the central atom cannot possibly have eight valence electrons. For example, LiCl, BeCl₂ and BCl₃ do not obey the octet rule.
Answer:
Significance of octet rule:
The octet rule successfully explained the formation of chemical bonds depending upon the nature of the element.
Limitations of the octet theory:
The following are the limitations of the octet rule:
(a) The rule failed to predict the shape and relative stability of molecules.
(b) It is based upon the inert nature of noble gases. However, some noble gases like xenon and krypton form compounds such as XeF2, KrF 2 etc.
(c) The octet rule cannot be applied to the elements in and beyond the third period of the periodic table. The elements present in these periods have more than eight valence electrons around the central atom. For example: PF5, SF6, etc. )
(d) The octet rule is not satisfied for all atoms in a molecule having an odd number of electrons. For example, NO and NO2 do not satisfy the octet rule.
(e) This rule cannot be applied to those compounds in which the number of electrons surrounding the central atom is less than eight. For example, LiCl, BeH 2, AlCl3 etc. do not obey the octet rule.
