(i) A yellow precipiate of the compound A is formed on passing H_(2)S through a neutral solution of the salt B. (ii) The compound A is soluble in hot dilute HNO_(3) but insoluble in yellow ammonium sulhpide. (iii) The The solution of B, on treatment with a small quantitity of NH_(3), gives a white precipitate soluble in an excess of the reagent, forming a compound C. (iv). The solution of B gives a white precipitate with a small concentration of KCN. the precipitate is soluble in an excess of the reagent, forming a compound D. (v) the solution of D, on treatment with H_(2)S, gives A. (vi) The solution of B in dilute HCl, on treatment with a solution of BaCl_(2), gives a white precipitate of the compound E, which is almost insoluble in concentrated HNO_(3). Q. Which of the following is the cation present in B?

(i) A yellow precipiate of the compound A is formed on passing H_(2)S

1.	(i) A yellow precipiate of the compound A is formed on passing H_(2)S through a neutral solution of the salt B. (ii) The compound A is soluble in hot dilute HNO_(3) but insoluble in yellow ammonium sulhpide. (iii) The The solution of B, on treatment with a small quantitity of NH_(3), gives a white precipitate soluble in an excess of the reagent, forming a compound C. (iv). The solution of B gives a white precipitate with a small concentration of KCN. the precipitate is soluble in an excess of the reagent, forming a compound D. (v) the solution of D, on treatment with H_(2)S, gives A. (vi) The solution of B in dilute HCl, on treatment with a solution of BaCl_(2), gives a white precipitate of the compound E, which is almost insoluble in concentrated HNO_(3). Q. Which of the following is the cation present in B?
Answer» `As^(3+)` `SB^(3+)` `Zn^(2+)` `Cd^(2+)` Solution :The YELLOW precipitate of a sulphide could be CdS (group IIA) or `As_(2)S_(3)//As_(2)S_(3)//SnS_(2)` (group IIB), but as it is insoluble ini yellow ammonium polysulphide, it should be CdS. Thus, the cation appears to Be `Cd^(2+)` which is confirmed by reactions (ii) to (V). reaction (vi) indicates `SO_(4)^(2-)`,. hence, the COMPOUND B is `CdSO_(4)`.