Question

What is the action of chlorine on excess $N{{H}_{3}}$?

Answer 1

Hint: Upon action of chlorine on excess of ammonia, a salt gets formed. The salt formed as a product has a coordinate bond. Overall a redox reaction occurs here where chlorine acts as an oxidizing agent.

Complete step by step answer:
When chlorine gas is allowed to react with an excess amount of ammonia gas, a redox reaction takes place. Let’s see what is the product and why it occurs.
- We know that chlorine has seven electrons in its valence shell and it needs just one electron to complete its octet. Its electronic configuration is $[Ne]3{{s}^{2}}3{{p}^{5}}$. Ammonia contains a nitrogen atom which has a lone pair of electrons which does not take part in the bonding.
- Ammonia and chlorine gas react to give Ammonium chloride and nitrogen gas. The reaction can be given as under.
     \[3C{{l}_{2}}+8N{{H}_{3}}\to 6N{{H}_{4}}Cl+{{N}_{2}}\]

- So, this is a redox type of reaction as chlorine in its molecular form has an oxidation state of zero and in ammonium chloride, it becomes -1. So, we can say that reduction of chlorine takes place here. Oxidation state of nitrogen is -3 in ammonia and becomes zero in nitrogen gas, so we can say that oxidation of ammonia occurs here.
- The product ammonium chloride contains a coordinate bond which is between nitrogen and a hydrogen atom. Ammonium chloride contains ammonium ion $(N{{H}_{4}}^{+})$ as a cation and chloride ion as an anion.

Note: Here, we are given that ammonia is in excess amount. If we are given that chlorine is present in excess amounts, then the reaction would be different. The excess of chlorine will allow the N-H bonds to be broken and new N-Cl bonds will be formed. The overall reaction can be given as under if chlorine is taken in excess amounts.
     \[3C{{l}_{2}}+N{{H}_{3}}\to NC{{l}_{3}}+3HCl\]