Question

When chlorine reacts with dil. $NaOH$ under cold conditions, the oxidation state of chlorine changes from zero to

• A. - 1 and + 5
• B. + 1 and + 4
• C. + 5 and +3
• D. - 1 and + 1

Answer 1

Answer: (D)

- 1 and + 1

Answer 2

When chlorine reacts with dilute and cold $NaOH$, sodium chloride and sodium hypochloride are formed.
$2 NaOH$ (cold) $+ Cl _{2} \rightarrow NaCl + \underset{\text{soldium hypochloride}}{NaClO} + H _{2} O$
Let oxidation state of $Cl$ in $NaCl$ is $x$.
$NaCl +1 + x =0 x=-1$
Let oxidation state of $Cl$ in
$NaClO$ is $x . NaClO$
$+1 + x -2 =0$
$x -1=0$
$x = + 1$
$\therefore$ Oxidation states of chlorine changes from
$0$ to $-1$ and $+1 .$