Chemistry - Ionic Equilibrium Question with Solution | TestHub

In$\mathrm{B}{\mathrm{F}}_3$, there is 2p$\mathrm{\pi }$-2p$\mathrm{\pi }$back bonding so its Lewis acidic character is less, similarly in$\stackrel{..}{\mathrm{O}}{\left(\mathrm{S}\mathrm{i}{\mathrm{H}}_3\right)}_2$there is 2p$\mathrm{\pi }$-3d$\mathrm{\pi }$back bonding, so it is a weak Lewis base$\mathrm{O}(\mathrm{C}{\mathrm{H}}_3{)}_2$is strong Lewis base and$\mathrm{B}\mathrm{B}{\mathrm{r}}_3$is strong Lewis acid so there show the best formation of adduct.
$\underset{\text{LA}}{{\text{BBr}}_{\text{3}}}\text{+}\underset{\text{LB}}{\text{O}{\left({\text{CH}}_{\text{3}}\right)}_{\text{2}}}\stackrel{}{\to }\underset{\left(\text{Adduct}\right)}{{{\text{(CH}}_{\text{3}}\text{)}}_{\text{2}}\text{O}\stackrel{}{\to }{\text{BBr}}_{\text{3}}}$