Question

Match List-I with the List-II

List-I (Precipitating reagent and conditions)	List-II (Cation)
(A) \(NH_4Cl + NH_4OH\)	(I) Mn2+
(B) \(NH_4OH + Na_2CO_3\)	(II) Pb2+
(C) \(NH_4OH + NH_4Cl + H_2S gas\)	(III) Al3+
(D) dilute HCl	(IV) Sr2+

Choose the correct answer from the options given below:

• A. A-IV, B-III, C-II, D-I
• B. A-IV, B-III, C-I, D-II
• C. A-III, B-IV, C-I, D-II
• D. A-III, B-IV, C-II, D-I

Answer 1

The Correct Option is C

To solve this problem, we match reagents and conditions from List-I with cations from List-II. Each reagent precipitates specific cations under given conditions:

1. (A) \(NH_4Cl + NH_4OH\):
   • This combination precipitates \(Al(OH)_3\) from solutions containing \(Al^{3+}\) ions.
2. (B) \(NH_4OH + Na_2CO_3\):
   • This combination precipitates carbonates of alkaline earth metals, such as \(SrCO_3\), indicating association with \(Sr^{2+}\).
3. (C) \(NH_4OH + NH_4Cl + H_2S\) gas:
   • In an alkaline medium (from \(NH_4OH\) and \((NH_4)_2S\)), sulfides of certain cations, like \(MnS\), can be precipitated. This matches with \(Mn^{2+}\).
4. (D) Dilute HCl:
   • This precipitates chlorides of certain metal ions, such as \(PbCl_2\). Therefore, it matches with \(Pb^{2+}\).

The correct matching is:

• (A) \(NH_4Cl + NH_4OH\) matches \(Al^{3+}\) (III).
• (B) \(NH_4OH + Na_2CO_3\) matches \(Sr^{2+}\) (IV).
• (C) \(NH_4OH + NH_4Cl + H_2S\) gas matches \(Mn^{2+}\) (I).
• (D) Dilute HCl matches \(Pb^{2+}\) (II).

The correct option is A-III, B-IV, C-I, D-II.