Question

Which of the following is the correct statement regarding $BOH$ (where $X$ is electronegativity)?

• A. If $X_O⎯X_B>X_O⎯X_H$, $BOH$ will be basic
• B. If $X_O⎯X_B<XO⎯XH$, $BOH$ will be acidic
• C. If $X_O⎯X_B>X_O⎯X_H$, $BOH$ will be acidic
• D. If $X_O⎯X_B<X_O⎯X_H$, $BOH$ will be basic

Answer 1

Answer: (A), (B)

If $X_O⎯X_B<XO⎯XH$, $BOH$ will be acidic

(a) If $X_O-X_B>X_O>X_H$, compound $BOH$ will be basic then $B-O$ will be more polar than $O-H$ bond and hence ionization of $BOH$ molecule in aqueous solution will take place at $B-O$ bond ${}^{\bullet }OH$ will be formed.
$B-O-H+H_{2}O\to \left[B\right(H_{2}O){]}^{+}+O{H}^{-}$
(b) If $X_O⎯X_B<XO⎯XH$, $BOH$ will be acidic then $O-H$ bond will be more polar than $B-O$ bond and hence ionization of $BOH$ molecule in aqueous solution will take place at $O-H$ bond and $H_3{O}^{+}$ ions will be formed .
$B-O-H+H_{2}O\to B{O}^{-}+H_3{O}^{+}$