Question

On adding ${{\text{H}}_{2}}\text{O}$ to $\text{BiC}{{\text{l}}_{2}}$ solution in $\text{HCl}$, the compound produced is:
A. $\text{B}{{\text{i}}_{2}}{{\text{O}}_{3}}$
B. $\text{Bi(OH}{{\text{)}}_{3}}$
C. $\text{BiOCl}$
D. $\text{BiOC}{{\text{l}}_{2}}$

Answer 1

Hint: Firstly, we have to study about the properties of bismuth chloride and then the process of bismuth chloride when it undergoes hydrolysis after the addition of water in hydrochloric acid.

Complete Step-by-Step Answer:
- In the given question, we have to identify the product which will be obtained when in bismuth chloride the water is added in the solution of hydrochloric acid.
- Let's study about the bismuth first. Bismuth chloride is also known as butter of bismuth which is an inorganic and a covalent compound. Moreover, bismuth chloride is widely used as a catalyst in many organic reactions.
- Whereas bismuth oxychloride is a lustrous and a white solid which is also known as pearl white. The formation of bismuth oxychloride takes place only from bismuth chloride.
- When the water is added in the bismuth chloride it undergoes hydrolysis due to which the one molecule of chlorine is removed from the $\text{BiC}{{\text{l}}_{2}}$ and the addition of oxygen take place.
- Along with that the formation of hydrochloric acid takes place.
- The balanced chemical reaction is:
\[\text{BiC}{{\text{l}}_{3}}\text{ + }{{\text{H}}_{2}}\text{O }\to \text{ BiOCl + 2HCl}\]
- Here, the bismuth chloride is oxidised as there is an addition of oxygen atom.
-The reaction can be reversed by the addition of hydrochloric acid.

Therefore, option C is the correct answer.

Note: When the water vapour is added in the bismuth chloride below a temperature of $\text{50}{}^\circ \text{C}$. The formation of monohydrate intermediate i.e. $\text{BiC}{{\text{l}}_{3}}.{{\text{H}}_{2}}\text{O}$ takes place. The compound is toxic and fatal when consumed by a person because it causes irritation in the gastrointestinal tract.