Salt Analysis Part 3
Salt analysis, also known as qualitative inorganic analysis, is a systematic method used to identify the cations and anions in an inorganic salt. This process involves preliminary tests, dry tests, and wet tests to determine the composition of unknown compounds. It plays a crucial role in chemistry labs, helping students and researchers analyze various salts efficiently.
- In salt analysis, which type of radical comes from an acid?
- a) Basic radical
- b) Acidic radical
- c) Amphoteric radical
- d) Neutral radical
(Answer: b) Acidic radical
- What is the role of ammonium hydroxide in qualitative inorganic analysis?
- a) Acts as a complexing agent
- b) Forms precipitates of hydroxides
- c) Helps in flame tests
- d) Removes water of crystallization
(Answer: b) Forms precipitates of hydroxides
2. Physical Properties of Salts
- Which cation imparts a yellow or brown color to inorganic salts?
- a) Cu²⁺
- b) Fe³⁺
- c) Pb²⁺
- d) Mn²⁺
(Answer: b) Fe³⁺
- A salt containing Ni²⁺ appears in which color?
- a) Pink
- b) Green or blue
- c) Red
- d) Yellow
(Answer: b) Green or blue
3. Flame Tests
- Which of the following cations does NOT give a flame test?
- a) Ca²⁺
- b) Be²⁺
- c) Na⁺
- d) K⁺
(Answer: b) Be²⁺
- What is the flame color of lithium (Li⁺) in a flame test?
- a) Violet
- b) Golden yellow
- c) Crimson red
- d) Apple green
(Answer: c) Crimson red
- Which ion imparts a brick-red color in a flame test?
- a) Sr²⁺
- b) Ca²⁺
- c) Na⁺
- d) K⁺
(Answer: b) Ca²⁺
4. Action of Heat
- Which of the following salts decomposes on heating to give CO₂?
- a) NaCl
- b) NaNO₃
- c) CaCO₃
- d) AgCl
(Answer: c) CaCO₃
- Which of the following halides decomposes when heated?
- a) NaCl
- b) FeCl₃
- c) KBr
- d) CaF₂
(Answer: b) FeCl₃
5. Solubility of Salts
- Which sulfate is insoluble in water?
- a) MgSO₄
- b) BaSO₄
- c) Na₂SO₄
- d) K₂SO₄
(Answer: b) BaSO₄
- Which of the following halides is highly soluble in water?
- a) AgCl
- b) PbI₂
- c) NaF
- d) AgBr
(Answer: c) NaF
6. Dry Tests
- Which gas is evolved when ammonium salts are heated with sodium hydroxide?
- a) SO₂
- b) NH₃
- c) H₂S
- d) CO₂
(Answer: b) NH₃
- The presence of sulfite (SO₃²⁻) is confirmed by:
- a) Evolution of CO₂
- b) Evolution of SO₂
- c) Formation of a brown precipitate
- d) None of the above
(Answer: b) Evolution of SO₂
- Which gas has a rotten egg smell?
- a) NH₃
- b) CO₂
- c) H₂S
- d) NO₂
(Answer: c) H₂S
7. Borax Bead Test
- Which ion gives a green bead in the oxidizing flame in the borax bead test?
- a) Cr³⁺
- b) Co²⁺
- c) Mn²⁺
- d) Cu²⁺
(Answer: a) Cr³⁺
- What is the color of cobalt metaborate in both oxidizing and reducing flames?
- a) Blue
- b) Green
- c) Red
- d) Brown
(Answer: a) Blue
8. Microcosmic Salt Bead Test
- In the microcosmic salt bead test, which metal ion gives a red color in a reducing flame?
- a) Cu²⁺
- b) Fe³⁺
- c) Co²⁺
- d) Mn²⁺
(Answer: a) Cu²⁺
9. Acid Radical Tests
- Which gas is evolved when carbonates react with dilute acid?
- a) SO₂
- b) NO₂
- c) CO₂
- d) H₂S
(Answer: c) CO₂
- Which of the following confirms the presence of sulfate (SO₄²⁻) ions?
- a) White precipitate with BaCl₂
- b) Effervescence with HCl
- c) Green color in the flame test
- d) None of these
(Answer: a) White precipitate with BaCl₂
10. Group Analysis of Cations
- Which of the following cations precipitate as sulfides in acidic medium?
- a) Pb²⁺, Cu²⁺, Hg²⁺
- b) Na⁺, K⁺, Ca²⁺
- c) Zn²⁺, Mn²⁺
- d) Ba²⁺, Sr²⁺
(Answer: a) Pb²⁺, Cu²⁺, Hg²⁺
- What is the characteristic precipitate color of Fe³⁺ hydroxide?
- a) Green
- b) Red-brown
- c) Blue
- d) Yellow
(Answer: b) Red-brown
11. Special Tests
- Which test is used to confirm the presence of nitrate (NO₃⁻) ions?
- a) Brown ring test
- b) Borax bead test
- c) Chromyl chloride test
- d) Nessler’s test
(Answer: a) Brown ring test
- What is the color of silver iodide (AgI) precipitate?
- a) White
- b) Yellow
- c) Black
- d) Brown
(Answer: b) Yellow
- Which metal ion forms a blue-colored complex with excess NH₄OH?
- a) Cu²⁺
- b) Fe³⁺
- c) Zn²⁺
- d) Ni²⁺
(Answer: a) Cu²⁺
- Which of the following cations form a yellow precipitate with potassium chromate (K₂CrO₄)?
- a) Pb²⁺
- b) Fe²⁺
- c) Cu²⁺
- d) Ag⁺
(Answer: a) Pb²⁺
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