pBlock ElementsII 2 Question 2
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2. Chlorine on reaction with hot and concentrated sodium hydroxide gives
======= ####2. Chlorine on reaction with hot and concentrated sodium hydroxide gives
3e0f7ab6f6a50373c3f2dbda6ca2533482a77bed (a) $\mathrm{Cl}^{-}$and $\mathrm{ClO}^{-}$
(b) $\mathrm{Cl}^{-}$and $\mathrm{ClO}_{3}^{-}$
(c) $\mathrm{ClO}{3}^{-}$and $\mathrm{ClO}{2}^{-}$
(d) $\mathrm{Cl}^{-}$and $\mathrm{ClO}_{2}^{-}$
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Solution:
- Halogens form halates and halides with hot and concentrated solution of $\mathrm{NaOH}$ as :
$$ 3 X_{2}+6 \mathrm{NaOH} \longrightarrow 5 \mathrm{NaX}+\mathrm{NaXO}{3}+3 \mathrm{H}{2} \mathrm{O} $$
So, $\mathrm{Cl}{2}$ will also give $\mathrm{Cl}^{-}$(as $\mathrm{NaCl}$ ) and $\mathrm{ClO}{3}^{-}$
(as $\mathrm{NaClO}_{3}$ ) in the above reaction.
Thus, option (b) is correct.
Note When halogens react with cold and dilute solution of $\mathrm{NaOH}$, hypohalites and halides are produced as:
$$ X_{2}+2 \mathrm{NaOH} \longrightarrow \mathrm{NaX}+\mathrm{NaXO}+\mathrm{H}_{2} \mathrm{O} $$
