$RX + \mathop {O{H^ - }}\limits_{Nucleophile} \to R - OH + {X^ - }$
$O^{-}$ stronger nucleophile than halogen so, easily replace the weaker nucleophile. Nucleophiles are either negative charge or lone pair of electrons bearing species, e.g. $O H^{-} ; \ddot{N H}_{3},$ etc
$i$ $. CH_3CO_2H$
$II.$ $ MeOCH_2CO_2H$
$III.$ $CF_3CO_2H$
$IV.$
$(i)$ $C{H_3} - \mathop C\limits^ + H - C{H_3}$
$(ii)$ $C{H_3} - \mathop C\limits^ + H - O - C{H_3}$
$(iii)$ $C{H_3} - \mathop C\limits^ + H - CO - C{H_3}$
$(I)$ $CH_2 = CH - C \equiv CH$
$(II)$ $CH \equiv C - C\equiv CH$
$(III)$ $CH_3 - CH = CH_2$
$(IV) $ $CH_2 = CH - C = CH_2$
$a$ અને $b$ વચ્ચે ની બંધ લંબાઈ નો સાચો ક્રમ કયો છે ?