Number of molecules having bond order 2 from the following molecules is . C2, O2, Be2, Li2, Ne2, N2, He2
Answer
2
Solution
Bond order = 12(Nb - Na)
C2 (12 e): KK 2s2 2s2 ( 2px2 = 2py2), so B.O. = 8 - 42 = 2
O2 (16 e): … ( 2px1 = 2py1), so B.O. = 10 - 62 = 2
N2: B.O. = 3; Li2: B.O. = 1; He2, Be2, Ne2: Nb = Na, so B.O. = 0.
Hence only C2 and O2 have bond order 2, i.e. 2 molecules.
Answer: 2