Question

Give the reaction of dichlorine gas with cold and dilute and hot and concentrated NaOH(aq).

Answer 1

Hint: Chlorine is an element of the halogen family. It has an atomic number 18. The dichlorine $C{l}_2$ is the gaseous molecule. At room temperature, it has a yellow-green color and it exists at very high temperatures too. Chlorine is very reactive which leads to many properties and reactions.

Complete step by step answer:
Dichlorine gas reacts with cold and diluted NaOH. The reaction is as follows:
$C{l}_2+2NaOH(coldanddil.)\to NaCl+NaClO+H_{2}O$
We can see that with cold and dilute NaOH, it forms NaCl and NaClO and water. NaClO is called sodium hypochlorite. In ionic form, the product can be written as $C{l}^{-}$ and $Cl{O}^{-}$.
In the above reaction, if we look at the oxidation state of Chlorine in reactants and products, we can see that chlorine gas with 0 oxidation state changes to $+1$in NaCl and $-1$ in NaClO. We know that when there is an increase in the oxidation number, oxidation has taken place, and if a decrease in oxidation number, the reduction has taken place.
 So, we can say that this is a disproportionation reaction because Chlorine is oxidized as well as reduced.
Dichlorine gas reacts with hot and concentrated NaOH and the reaction is as follows:
$6NaOH+3C{l}_2\to 5NaCl+NaCl{O}_3+3H_{2}O$ .
It is also a disproportionation reaction. The oxidation number is changed from 0 to $-1$ and $+5$.

Note: chlorine has got a very pungent smell and if some breathe it too much, it can lead to suffocation. Dichlorine gas reacts with almost all elements except noble gases. It reacts with ammonia too. It reacts with hydrogen, metals, and non-metals too. With alkalis, a variety of products can be observed.