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

Answer

D

Explanation

Structures of `CO_(2),CO` and `CO_(3)^(2-)` are

Bond multiplicity decreases the bond length. Thus, `CO` with a triple bond will have shortest `C-O` bond length. `CO_(2)` with a double bond will have a larger `C-O` bond length. `CO_(3)^(2-)` is a resonance hybrid of three structures with a `C-O` length of more than a `C-O` double but less than a `C-O` single bond. thus, `C-O` bond length is maximum in `CO_(3)^(2-)`.