$H _2 \ddot{ O :} \longrightarrow \text { Lewis base }$
$BF _3 \longrightarrow \text { Lewis acid }$
$\ddot{ :O :}H \longrightarrow \text { Lewis base }$
$\ddot{ N } H _3 \longrightarrow \text { Lewis base }$
$(a)$ $ 10^{-10}$ $(b)$ $\frac{{Kw}}{{{{10}^{ - 10}}}}$ $(c)$ $\frac{{Kw}}{{{{10}^{ - 8}}}}$ $(d)$ $10^{-4}$
(ગ્લીસરીન માટે $Ka_1 = 4.5\times 10^{-3}$, $Ka_2 =1.7 \times 10^{-10}$ )