Question:
$\mathrm{H}_{3} \mathrm{PO}_{3}$ can be represented by structures 1 and 2 shown below. Can these two structures be taken as the canonical forms of the resonance hybrid representing $\mathrm{H}_{3} \mathrm{PO}_{3}$ ? If not, give reasons for the same
Solution:
The given structures cannot be taken as the canonical forms of the resonance hybrid of H3PO3 because the positions of the atoms have changed.