How many ions of the following have bond order of 2.5 ?
`N_2,NO^-,C_2^-, N_2^+,C_2^(2-), CN^+`

Options

A. 4
B. 3
C. 2
D. 5

Answer

B

Explanation

Bond order
`("Number of bonding electrons"-"Number of anti-bonding electrons")/2`
`"Bond order of "N_2^(-)" is "((10-5))/2=6/2=2.5`
`"Bond order of "NO^(-)" is "((10-6))/2=4/2=2`
`"Bond order of "C_2^(-)" is "1/2(9-4)=5/2=2.5`
`"Bond order of "N_2^(+)" is "((9-4))/2=5/2=2.5`
`"Bond order of "C_2^(2-)" is "((10-4))/2=6/2=3`
`"Bond order of "CN^(+)" is "((8-4))/2=2`