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Chemistry Homework Help => CBSE XI and XII Chemistry => Topic started by: Pranjal Singh on September 20, 2020, 12:31:26 AM

Title: No Hybridisation of atoms-Drago rule
Post by: Pranjal Singh on September 20, 2020, 12:31:26 AM
Here it is
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Title: Re: No Hybridisation of atoms-Drago rule
Post by: uma on September 20, 2020, 11:01:25 AM
To answer this question we need to know Drago rule .According to Drago Rule -If
the central atom has at least one lone pair of electron on it and it belongs to  group 13,14 ,15 or 16 and is from 3rd to 7th period.
if electronegativity of central element is 2.5 or less and total groups around it are  four =no. of sigma bonds+ lone pair
Like NH3 uses sp3 hybridization but PH3 and AsH3  extend of hybridization is less.
This is due big differences in the size and energy  of hybridized orbitals overlapping with 1s orbital of H atom  to form bonds.
In these cases  there is no hybridization and atom will use pure orbitals for bonding.
It means as you go down the group then hybridization effect decreases ...like P or S atoms are big in size .However in PCl3,Cl orbital size is comparable with P so overlapping is feasible with hybridized orbitals.
However in S(CH3)2, size and energy  of C and S orbitals are not comparable so S will not undergo hybridization.