Question

In $2Na(s) + C{l_2} \to 2NaCl(s)$: The oxidising is ____

Answer 1

Hint: There are two types of reactions: one is oxidation and second is reduction. When these two reactions occur simultaneously, then it is known as redox reaction. The compound which oxidises others is an oxidising agent and the compound which helps in reducing other compounds is called reducing agent.

Complete answer:
Oxidation is also referred to as when a substance goes from lower to higher oxidation state whereas Reduction is called when a substance goes from higher to lower oxidation state. When these two reactions occur simultaneously, then it is known as redox reaction.
So, we now know what oxidation and reduction reactions are now we will know about what are oxidising and reducing agents in this reaction.
The substance which gives oxygen for oxidation or removes hydrogen is an oxidising agent. The substance which gives hydrogen for reduction or removes oxygen is a reducing agent.
Also the oxidising agent can be the substance which makes the other substance to go from lower oxidation state to higher oxidation state and gets reduced itself while the reducing agent can be the substance which makes the other substance to go from higher oxidation state to lower oxidation state and gets oxidised itself.
Now, in the given reaction:
$2Na(s) + C{l_2} \to 2NaCl(s)$
$Na$ is getting oxidised from $0$ oxidation state to the $ + 1$ Oxidation state while Chlorine is being reduced from $0$ oxidation state to the $ - 1$ oxidation state.
Hence, chlorine $(C{l_2})$ is being reduced itself and oxidising the sodium metal and we can say that chlorine is the oxidising agent in the above reaction.

Note:
To identify oxidising agents and reducing agents in a reaction, we have to notice the change in their oxidation state from reactant side to product side. If the change in oxidation state is positive, then it is a reducing agent and oxidises itself and if the change in oxidation state is negative, then it is an oxidising agent and reduces itself.