The correct order of decreasing `C-O` bond length of (1) `CO,(II)CO_(3)^(2-) (III)CO_(2)` is .

Options

A. `CO_(3)^(2) lt O_(2) lt O_(2)^(-)`
B. `CO_(2) lt CO_(3)^(2-) lt CO`
C. `CO lt CO_(3)^(2-) lt CO_(2)`
D. `CO lt CO_(2) lt CO_(3)^(2-)`

Answer

d

Explanation

Bond length `= (1)/("Bond order")`
Bond order `CO_(3)^(2-) lt CO_(2) lt CO` ltbr Bond order in `CO = 3` (with the help of molecular orbital theory)
Bond order in `CO_(2) = ("No of bond in all possible sides")/("No of resonating structure")`
(by resonance)
`= (4)/(2) = 2`
Bond ordre in `CO_(3)^(2-) = (4)/(3) = 1.33` (by resonance)
So order of bond length of `C = O`
`CO lt CO_(2) lt CO_(3)^(2-)`