Question

Account for the following:
Carbon-oxygen bond lengths in formic acid are$1.23\mathring{A}$ and $1.36\mathring{A}$ but in sodium formate both carbon-oxygen bonds have same value ie., $1.27\mathring{A}$

Answer 1

The formate ion present in sodium formate is a resonance hybrid of the following two structures
Thus, in resonance hybrid the bond length of $C-O$ are identical. In formic acid, no such resonance exists and thus, the bond lengths are different