Answer :

Final Answer:

The identity of the anion in Unknown #103 is carbonate [tex](CO_3^2-)[/tex].

Explanation:

The identity of an unknown anion can often be determined through chemical analysis. In this case, the anion in Unknown #103 can be identified by performing a series of chemical tests. One common test involves reacting the unknown compound with an acid to determine its acidity or basicity. In the case of Unknown #103, when reacted with hydrochloric acid (HCl), it produces carbon dioxide [tex](CO_2)[/tex] gas, indicating the presence of carbonate ions [tex](CO_3^2-)[/tex].

This is confirmed by the formation of a white precipitate when a solution of Unknown #103 is treated with calcium chloride [tex](CaCl_2)[/tex], which forms calcium carbonate [tex](CaCO_3)[/tex] as an insoluble salt. Therefore, based on these observations, the identity of the anion in Unknown #103 is carbonate [tex](CO_3^2-)[/tex].

Additionally, the carbonate ion [tex](CO_3^2-)[/tex] is known to have a characteristic reaction with acids, where it forms carbon dioxide gas [tex](CO_2)[/tex].This reaction can be represented by the equation:[tex]CO_3^2- + 2H^+ - > CO_2 + H_2O[/tex].The formation of carbon dioxide gas is indicative of the presence of carbonate ions in the unknown compound.

Furthermore, the reaction with calcium chloride confirms the presence of carbonate ions, as calcium carbonate is a white insoluble precipitate. This qualitative analysis method is commonly used in chemistry laboratories to identify unknown ions in compounds.

In conclusion, through chemical tests involving the reaction with hydrochloric acid and calcium chloride, the identity of the anion in Unknown #103 is determined to be carbonate [tex](CO_3^2-)[/tex]. This identification is based on the characteristic reactions of carbonate ions with acids to produce carbon dioxide gas and with calcium ions to form insoluble calcium carbonate precipitate. Such qualitative analysis techniques are essential in identifying unknown ions in chemical compounds.