Question

The products obtained when chlorine gas reacts with cold and dilute aqueous \[{\text{NaOH}}\] are:
A.\[{\text{Cl}}{{\text{O}}^{^ - }}{\text{and ClO}}_3^ - \]
B.\[{\text{ClO}}_2^ - \,{\text{and ClO}}_3^ - \]
C.\[{\text{C}}{{\text{l}}^ - }{\text{ and Cl}}{{\text{O}}^{^ - }}\]
D.\[{\text{C}}{{\text{l}}^ - }{\text{ and ClO}}_2^ - \,\]

Answer 1

Hint: In the above reaction of sodium hydroxide with chlorine the formation of salt occurs along with water. Two types of salt form, one of them is common salt.

Complete step by step answer:
Sodium hydroxide is an alkali, the whole aqueous solution is basic in nature. The dilute solution is that solution in which amount of solute is very less than solvent. And chlorine in gaseous form exists as a diatomic molecule.
The reaction of cold and dilute sodium hydroxide that is \[{\text{NaOH}}\] when reacts with chlorine gas occurs as follow:
\[2{\text{NaOH}} + {\text{ C}}{{\text{l}}_2} \to {\text{NaCl}} + {\text{NaClO}} + {{\text{H}}_2}{\text{O}}\]
One of the products formed is common salt. Sodium chloride is an ionic salt and ionizes in aqueous solution into its respective ions as follow:
\[{\text{NaCl}} \to {\text{N}}{{\text{a}}^ + } + {\text{C}}{{\text{l}}^ - }\]
So in the solution sodium and chloride ions are present. But in option A and B chloride ions are not given. Hence option A and B stands eliminated.
The other salt formed is sodium hypochlorite; it also ionizes in water just like common salt as follow:
\[{\text{NaClO}} \to {\text{N}}{{\text{a}}^ + } + {\text{Cl}}{{\text{O}}^ - }\]
In the solution Sodium ion and hypochlorite ion are present.

The correct option is C.

Note:
Sodium hypochlorite has a molecular formula \[{\text{NaClO}}\].It is known as sodium salt of hypochlorous acid. The common name of sodium hypochlorite is bleach. In households it is often used as a liquid bleach as a disinfectant. The basic principle about the above property is that the compound sodium hypochlorite is relatively unstable and breakdown, gives chlorine gas which is well known for having the above mentioned properties.