Quiz: Analytical Chemistry Using Alkali!
Questions and Answers
- 1.
Among the following cations which one is a coloured ion?
- A.
Sodium ion
- B.
Potassium ion
- C.
Zinc ion
- D.
Ferric ion
- E.
Calcium ion
- F.
None of the above
Correct Answer
D. Ferric ionExplanation
among the above mentioned ions ferric ion is yellow or brown in colourRate this question:
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- 2.
Among the following anions which one is colourless ion?
- A.
Chromate ion
- B.
Dichromate ion
- C.
Permanganate ion
- D.
Nitrate ion
Correct Answer
D. Nitrate ionExplanation
chromate ion is yellow
dichromate is orange
permanganate is purple or violetRate this question:
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- 3.
Solution of which of the following salts will become a deep inky blue when excess of an ammonium hydroxide solution is added to it ?
- A.
Copper(II)nitrate
- B.
Iron(II)sulphate
- C.
Iron(III)chloride
- D.
Lead(II)nitrate
- E.
Magnesium sulphate
- F.
Zinc chloride
Correct Answer
A. Copper(II)nitrateExplanation
When excess ammonium hydroxide solution is added to Copper(II)nitrate, it forms a deep inky blue solution. This is because the copper(II) ions in the salt react with the ammonium hydroxide to form a complex ion called tetraamminecopper(II) ion, which has a deep blue color. This reaction is specific to copper(II) ions and is used as a test for the presence of copper(II) ions in a solution.Rate this question:
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- 4.
The solution of the which of the folowing salt should be colourless ?
- A.
Iron(II)sulphate
- B.
Copper(II)sulphate
- C.
Iron(III)chloride
- D.
Zinc(II)nitrate
Correct Answer
D. Zinc(II)nitrateExplanation
Zinc(II)nitrate should be colorless because zinc ions do not have any unpaired electrons in their d orbitals, which means they do not absorb visible light and do not exhibit any color. In contrast, iron(II)sulphate, copper(II)sulphate, and iron(III)chloride contain transition metal ions that have unpaired electrons and can absorb certain wavelengths of light, resulting in colored solutions.Rate this question:
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- 5.
Which of the following hydroxide will turn black on heating?
- A.
Iron(II)hydroxide
- B.
Iron(III)hydroxide
- C.
Zinchydroxide
- D.
Copperhydroxide
Correct Answer
D. CopperhydroxideExplanation
Copper hydroxide will turn black on heating because it undergoes thermal decomposition, resulting in the formation of copper oxide and water. The black color is due to the formation of copper oxide, which is a black solid.Rate this question:
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- 6.
A yellow monoxide that dissolves in hot and concentrated caustic alkali 8
- A.
PbO
- B.
ZnO
- C.
Al2O3
- D.
CuO
Correct Answer
A. PbOExplanation
PbO is the correct answer because it is a yellow monoxide that dissolves in hot and concentrated caustic alkali. The other options, ZnO, Al2O3, and CuO, do not meet the criteria mentioned in the question.Rate this question:
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- 7.
Name a chloride of metal which dissolves in excess of ammonium hydroxide ?
- A.
Lead(II)chloride
- B.
Copper(II)chloride
- C.
Silverchloride
- D.
Sodiumchloride
Correct Answer
C. SilverchlorideExplanation
Silver chloride is the correct answer because it is the only chloride of metal that dissolves in excess of ammonium hydroxide. Lead(II) chloride, copper(II) chloride, and sodium chloride do not dissolve in excess of ammonium hydroxide.Rate this question:
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- 8.
Among mentioned chemical compound which one acts as amphoteric oxide I. Alumininium oxide II.Zinc oxide III.Copper(II)oxide IV.Lead(II)oxide
- A.
I
- B.
I, II,
- C.
I, II ,III
- D.
I, II, IV
- E.
All of the above
Correct Answer
D. I, II, IVExplanation
Aluminium oxide, Zinc oxide, and Lead(II) oxide all act as amphoteric oxides. This means that they can react as both an acid and a base. They can react with both acids and bases to form salts. Copper(II) oxide, on the other hand, is a basic oxide and does not have amphoteric properties. Therefore, the correct answer is I, II, and IV.Rate this question:
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- 9.
Name two base which are not alkali but dissolves in excess of alkali?
- A.
Aluminium hydroxide and Sodium hydroxide
- B.
Lead(II)hydroxide and Copper(II)hydroxide
- C.
Aluminium hydroxide and Lead(II)hydroxide
Correct Answer
C. Aluminium hydroxide and Lead(II)hydroxideExplanation
Aluminium hydroxide and Lead(II)hydroxide are two bases that are not alkali but can dissolve in excess alkali. This means that when they are added to an excess of alkali solution, they will react and form soluble compounds. Alkalis are typically bases that are soluble in water, but these two bases are exceptions to that rule. They can still react with alkali solutions, but they do not themselves dissolve readily in water.Rate this question:
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- 10.
On adding dilute ammonia solution to a colourless solution of a salt , a white geletinious precipitate appears. This precipitate however dissolves on addition of excess of ammonia solution. Identify Which metal salt solution was used ?
- A.
Na
- B.
Al
- C.
Zn
- D.
Pb
- E.
Fe
Correct Answer
C. ZnExplanation
The white gelatinous precipitate that appears when dilute ammonia solution is added to the colorless solution of a salt is a characteristic reaction of zinc salts. This precipitate is zinc hydroxide, which is insoluble in water. However, when excess ammonia solution is added, it forms a soluble complex with zinc, resulting in the dissolution of the precipitate. Therefore, the metal salt solution used in this case is likely a zinc salt.Rate this question:
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