Question

Question 4.29 Considering x-axis as the internuclear axis which out of the following will not form a sigma bond and why?

(a) 1s and 1s

(b) 1s and 2px

(c) 2py and 2py

(d) 1s and 2s.

Class XI Chemical Bonding and Molecular Structure Page 131

Answer 1

2py & 2py bcoz taking x axis as internuclear axis , they do collateral overlapping & form pi bond.

Answer 2

concept :- axial overlapping results in the formation of sigma bond. and sideways overlapping results in the formation of pi bond .
sigma bond involves overlapping of s - s , s - p and p - p atomic orbitals .


only (c ) won't form sigma bond . because on taking x - axis as the internuclear axis, 2py and 2py orbitals overlap sideway ( lateral overlapping ) resulting in the formation of pi bond .
hence, option ( c ) is answer .