Question

When chlorine is passed through hot concentrated caustic soda solution, the oxidation number of chlorine in one of the products increases from:

• A. $0$ to $+7$
• B. $-1$ to $+7$
• C. $0$ to $+5$
• D. $0$ to $-1$

Answer 1

The correct option is C $0$ to $+5$

Chlorine reacts with a hot concentrated $NaOH$ solution to form sodium chloride and sodium chlorate. The oxidation number of chlorine increases from $0$ (in chlorine element) to $+5$ (in sodium chlorate) and decreases from $0$ to $-1$ (in sodium chloride).

The reaction is as follows:

$3C{l}_2+6NaOH\to 5NaCl+NaCl{O}_3+3H_{2}O$

Hence, option $C$ is the correct answer.