Chemistry - CHEMICAL BONDING Question with Solution | TestHub

The underlined O in THF retains four electron domains in its borane donor adduct, so A does not change its assigned sp³ hybridisation. Bicarbonate decomposition gives carbonate, water and CO₂; the underlined oxygen can enter CO₂, whose conventional O hybridisation is sp² rather than the hydroxyl O's sp³. Thus B qualifies. Boric acid accepts OH⁻ to make B(OH)₄⁻, changing the underlined B from trigonal sp² to tetrahedral sp³: C qualifies. Diborane/ammonia products have tetrahedral boron environments in the source model, so D is not selected. Answer B,C. The oxygen underline in B is essential.