When HCl gas is passed through a saturated solution of \[\text{BaC}{{\text{l}}_{\text{2}}}\]​, a white ppt is obtained. This is due to
(A) Impurities in \[\text{BaC}{{\text{l}}_{\text{2}}}\]​
(B) Impurities in HCl
(C) Precipitation in \[\text{BaC}{{\text{l}}_{\text{2}}}\] ​
(D) Formation in complex.

Hint: An inorganic substance with the formula \[\text{BaC}{{\text{l}}_{\text{2}}}\] is barium chloride. It is one of the most popular barium salts that dissolve in water. Like the majority of other water-soluble barium salts, it is white, extremely hazardous, and gives flames a yellow-green tint. Additionally, it is hygroscopic, first converting to the dihydrate.

Complete Step by Step Solution:
A type of reaction called a double displacement reaction involves the exchange of ions between two reactants to create two new molecules. Precipitates are frequently formed as a byproduct of double displacement processes. Although technically the bonds created between the chemical species may be either ionic or covalent in nature, the reaction most frequently happens between ionic compounds.

Double displacement processes also involve bases or acids. The bonds created in the reactant molecules are the same kind of bonds that are created in the result compounds. Water is frequently used as the solvent in this kind of reaction.

Two aqueous ionic compounds undergo a precipitation reaction to create a new, insoluble ionic compound. A white ppt is produced when HCl gas is passed through a saturated solution of \[\text{BaC}{{\text{l}}_{\text{2}}}\]. The precipitation in \[\text{BaC}{{\text{l}}_{\text{2}}}\] is to blame for this. As the \[\text{C}{{\text{l}}^{-}}\] ion concentration rises as a result of the addition of HCl, the ionic product becomes higher than the solubility product, and \[\text{BaC}{{\text{l}}_{\text{2}}}\]precipitates as a white precipitate.
Hence option (C) is correct.

Note: When one or more of the reactants do not dissolve in the solvent, the reaction is referred to as a double decomposition reaction. Other names for a double displacement reaction include salt metathesis, exchange, and double replacement.