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Q. No.A white precipitate obtained in the analysis of a mixture becomes black on treatment with \(\mathrm{NH_4OH}.\) It may be:
1. \(\mathrm{PbCl_2}\)
2. \(\mathrm{AgCl}\)
3. \(\mathrm{HgCl_2}\)
4. \(\mathrm{Hg_2Cl_2}\)
1. \(\mathrm{PbCl_2}\)
2. \(\mathrm{AgCl}\)
3. \(\mathrm{HgCl_2}\)
4. \(\mathrm{Hg_2Cl_2}\)
Subtopic: Detection of Cations |
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Consider the following sequence of tests:
\(M^{n+} ~+ HCl \rightarrow \) White precipitate \(\xrightarrow \Delta \) water soluble
The metal ion \((M^{n+})\)) can be:
1. \(Hg^{2+}\)
2. \(Ag^{+}\)
3. \(Pb^{2+}\)
4. \(Sn^{2+}\)
\(M^{n+} ~+ HCl \rightarrow \) White precipitate \(\xrightarrow \Delta \) water soluble
The metal ion \((M^{n+})\)) can be:
1. \(Hg^{2+}\)
2. \(Ag^{+}\)
3. \(Pb^{2+}\)
4. \(Sn^{2+}\)
Subtopic: Detection of Cations |
52%
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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. None of the above
(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. None of the above
Subtopic: Detection of Cations |
67%
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Which functional group gives a positive test with 2,4-Dinitrophenylhydrazine (2,4-DNPH) reagent?
1. Alcohol (-OH)
2. Ketone (C=O)
3. Carboxylic acid (COOH)
4. Ester (RCOO-)
1. Alcohol (-OH)
2. Ketone (C=O)
3. Carboxylic acid (COOH)
4. Ester (RCOO-)
Subtopic: Detection of the functional groups |
82%
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What is formed when a carbonyl compound reacts with Tollens' reagent (ammoniacal silver nitrate)?
1. White precipitate
2. Red coloration
3. Silver mirror
4. Blue solution
1. White precipitate
2. Red coloration
3. Silver mirror
4. Blue solution
Subtopic: Detection of the functional groups |
87%
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Which reagent is used to distinguish between saturated and unsaturated hydrocarbons?
1. Bromine water (Br2)
2. Silver nitrate (AgNO3)
3. Hydrochloric acid (HCl)
4. Potassium permanganate (KMnO4)
1. Bromine water (Br2)
2. Silver nitrate (AgNO3)
3. Hydrochloric acid (HCl)
4. Potassium permanganate (KMnO4)
Subtopic: Detection of the functional groups |
73%
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What is the product formed when a ketone reacts with 2,4-Dinitrophenylhydrazine (2,4-DNPH) reagent?
1. Orange/green precipitate
2. Silver mirror
3. White precipitate
4. Yellow/orange precipitate
1. Orange/green precipitate
2. Silver mirror
3. White precipitate
4. Yellow/orange precipitate
Subtopic: Detection of the functional groups |
77%
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Which reagent from the options provided is capable of differentiating between aldehydes and ketones during salt analysis?
1. Lucas test
2. Bromine water
3. 2,4-DNP test
4. Schiff's reagent
1. Lucas test
2. Bromine water
3. 2,4-DNP test
4. Schiff's reagent
Subtopic: Detection of the functional groups |
59%
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What is the purpose of the borax bead test?
1. To identify the presence of specific metallic ions
2. To determine the acidity of a solution
3. To test for the presence of organic compounds
4. To measure the concentration of a solute
1. To identify the presence of specific metallic ions
2. To determine the acidity of a solution
3. To test for the presence of organic compounds
4. To measure the concentration of a solute
Subtopic: Detection of extra elements |
81%
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What is the role of borax (sodium borate) in the borax bead test?
1. It acts as a flux to facilitate the formation of a bead.
2. It acts as an indicator for pH changes.
3. It reacts with metal ions to form colored complexes.
4. It stabilizes the flame during heating.
1. It acts as a flux to facilitate the formation of a bead.
2. It acts as an indicator for pH changes.
3. It reacts with metal ions to form colored complexes.
4. It stabilizes the flame during heating.
Subtopic: Detection of extra elements |
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