Which of the following cations precipitate as their chlorides? 

(a) \(Pb^{2+}\)
(b) \(Ag^{+}\)
(c) \(Hg^{2+}_2\)
(d) \(Cd^{2+}\) 

1. (a), (b), (d)
2. (b) and (c) 
3. (a), (b), (c)
4. None of the above

Subtopic:  Detection of Cations |
 74%
Level 2: 60%+
Hints

A white sublimable solid, when boiled with an \(NaOH\) solution, gives a colourless gas that turns Nessler's reagent brown. The solid, on being heated with solid \(K_2Cr_2O_7\) and concentrated \(H_2SO_4,\) gives red brown vapours. The white solid can be :

(a) \(NH_4I\)
(b) \(NH_4Br\)
(c) \(NH_4Cl\)
(d) \((NH_4)_2SO_4\) 

1. (a), (b), (d)
2. (b) and (c) 
3. (a), (b), (c)
4. None of the above
Subtopic:  Detection of Cations |
 53%
Level 3: 35%-60%
Hints

The cation which gives yellow ppt with \(K_2CrO_4 \) in acetic acid is:

(a) \(Ba^{2+}\)
(b) \(Pb^{2+}\)
(c) \(Ca^{2+}\)
(d) \(Al^{3+}\)

1. (a) and (b)
2. (b) and (c) 
3. (a), (b) and (c)
4.  (a), (b), (c) and (d)
Subtopic:  Detection of Cations |
Level 3: 35%-60%
Hints

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On reaction with dilute \(H_2SO_4,\) which of the following salts will give out a gas that turns an acidified dichromate paper green?

(a) \(Na_2CO_3\)
(b) \(Na_2S\)
(c) \(ZnSO_3\)
(d) \(FeS\)

1. (b), (c), (d)
2. (b) and (c) 
3. (a), (b), (c)
4. None of the above
 
 
Subtopic:  Detection of Cations |
 64%
Level 2: 60%+
Hints

Which of the following cations cannot be separated by passing \(H_2S\) through their solutions to which \(NH_4OH\) has been added?
(a) \(Ca^{2+}\) and \(Ni^{2+}\)
(b) \(Mg^{2+}\) and \(Mn^{2+}~\)
(c) \(Ni^{2+}\) and \(Mn^{2+}\)
(d) \(Co^{2+}\) and \(Zn^{2+}\)

1. (a), (b), (d)
2. (c) and (d) 
3. (a), (b), (c)
4. (b) Only
Subtopic:  Detection of Cations |
 64%
Level 2: 60%+
Hints

Incorrect statements among the following are:
(a) Group I radicals are precipitated as chloride
(b) Group IV radicals are precipitated as sulphide
(c) Group V radicals are precipitated as hydroxide
(d) Group III radicals are precipitated as chloride
1. (a), (b) and (d)
2. (c) and (d) 
3. (a), (b) and (c)
4. (a), (b), (c) and (d)
Subtopic:  Detection of Cations |
 61%
Level 2: 60%+
Hints

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\(Fe^{3+},Zn^{2+}\) and \(Cu^{2+}.\) cations are present in a slightly acidic solution. The reagent that when added in excess to this solution would identify to separate \(Fe^{3+}\) in one step is:

1. \(2M~HCl \)
2. \(6M~NH_3 \)
3. \(6M~NaOH \)
4. \(H_2S~\) gas
Subtopic:  Detection of Cations |
Level 3: 35%-60%
Hints

An aqueous solution of a substance gives a white precipitate on treatment with dilute hydrochloric acid, which dissolves on heating. When hydrogen sulfide is passed through the hot acidic solution, a black precipitate is obtained.
The substance is a:

1. \(Hg^{2+}_2\) salt 
2. \(Cu^{2+}\) salt 
3. \(Ag^+\) salt 
4. \(Pb^{2+}\) salt 
Subtopic:  Detection of Cations |
 74%
Level 2: 60%+
Hints

A solution when diluted with \(H_2O\) and boiled, gives a white precipitate. Upon addition of excess \(NH_4Cl/NH_4OH, \)the volume of precipitate decreases, leaving behind a white gelatinous precipitate. Identify the precipitate that dissolves :

1. \(Al(OH)_3\)
2. \(Z n(OH)_2\)
3. \(Ca(OH)_2\)
4. \(Mg(OH)_2\)
Subtopic:  Detection of Cations |
Level 3: 35%-60%
Hints

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An aqueous solution of metal ion M1 reacts separately with reagents Q and R in excess to give tetrahedral and square planar complexes, respectively. An aqueous solution of another metal ion M2 always forms tetrahedral complexes with these reagents. Aqueous solution of M2 on reaction with reagent S gives a white precipitate which dissolves in excess of S.
M1, Q, and R, respectively, are:

1. \(Zn^{2+}, ~ KCN\) and \(HCl\)
2. \(Ni^{2+},~ HCl\) and \(KCN\)
3. \(Cd^{2+}, ~KCN\) and \(HCl\)
4. \(Co^{2+},~ HCl\) and \(KCN\)
 
Subtopic:  Detection of Cations |
 65%
Level 2: 60%+
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