Chemical Reagents to Test for Anions in Solution

One of the following pairs of chemical reagents which are most appropriate is used to test for the presence of an anion of inorganic salts.

i. Dilute barium chloride solution, BaCl₂(aq), and dilute hydrochloric acid solution, HCl(aq) 

ii. Dilute barium trioxonitrate (V) solution, Ba(NO₃)₂(aq), and dilute trioxonitrate (V) acid, HNO₃(aq); 

iii. Dilute aqueousA solution in which the solvent is water. is called an aqueous solution. It is mostly shown in chemical equations by appending (aq) to the relevant chemical formula. For example, a... More silver trioxonitrate (V) solution, AgNO₃(aq), and dilute trioxonitrate (V) acid, HNO₃(aq)

iv. Freshly prepared aqueous Iron (II) tetraoxosulphate (IV) FeSO₄(aq), with concentrated tetraoxosulphate (VI) acid, H₂SO_4, is used to test for trioxonitrate (V) nitrate ion, NO^–3

v. And a few others.

Note that often the pair in (i) and (ii) give same result.