Chemistry - GOC Question with Solution | TestHub

Here hybridisation of oxygen is$\mathrm{s}{\mathrm{p}}^3$. so it cannot be a planar molecule. In it lone pair of oxygen does not involve in delocalisation, otherwise it will become antiaromatic compound. Rest other are planar as they have only$\mathrm{s}{\mathrm{p}}^2$hybridisation.