Question

$C{H}_{3}Br+N{u}^{-}\to C{H}_3-Nu+B{r}^{-}$
The decreasing order of the rate of the above reaction with the following nucleophiles $\left(N{u}^{-}\right)$ $A$ to $D$ is:
A) $Ph{O}^{-}$ B) $Ac{O}^{-}$ C) $H{O}^{-}$ D) $C{H}_{3}C{H}_2{O}^{-}$

• A. $D>C>A>B$
• B. $D>C>B>A$
• C. $A>B>C>D$
• D. $B>D>C>A$

Answer 1

The correct option is A $D>C>A>B$

$C{H}_{3}Br+N{u}^{-}\to C{H}_3-Nu+B{r}^{-}$
Making conjugate bases of all :
i) $PHOH\to H^{+}+PH{O}^{-}$
Acid Base
(Weak) (Strong)
ii) $A_{c}OH\to H^{+}+A_c{O}^{-}$
Acid Base
(Weak) (Strong)
iii) $H_{2}O\to H^{+}+O{H}^{-}$
Acid Base
(Weak) (Strong)
iv) $C{H}_{3}C{H}_{2}OH\to H^{+}+C{H}_{3}C{H}_2{O}^{-}$
Acid Base
(Weakest) (Strongest)
All alcohols are weaker acids than $H_{2}O$.