Qualitative Analysis - NEET Previous Year Questions

Chapter Overview

Qualitative Analysis is a practical and systematic chapter in Inorganic Chemistry that deals with the identification of ions and compounds through chemical tests. This chapter consistently contributes 2-3 questions annually in NEET, making it important for scoring well. The chapter covers systematic analysis of cations and anions, separation techniques, confirmatory tests, and complexometric titrations.

Weightage Analysis

• Average Questions per Year: 2-3
• Success Rate: 70-75%
• Difficulty Level: Easy to Medium
• Most Important Topics: Group analysis, Confirmatory tests, Precipitation reactions

Section-wise Distribution

Cation Analysis (60% of questions)

• Group I: Pb²⁺, Ag⁺ (HCl/H₂SO₄ precipitate)
• Group II: Hg²⁺, Cu²⁺, Bi³⁺, Cd²⁺, As³⁺ (H₂S in acidic medium)
• Group III: Fe³⁺, Al³⁺, Cr³⁺ (NH₄OH in neutral medium)
• Group IV: Mn²⁺, Co²⁺, Ni²⁺, Zn²⁺ (H₂S in basic medium)
• Group V: Ba²⁺, Ca²⁺, Sr²⁺, Mg²⁺ (NH₄)₂CO₃
• Group VI: NH₄⁺ (NaOH)

Anion Analysis (30% of questions)

• Group A: SO₄²⁻, PO₄³⁻, CO₃²⁻ (BaCl₂ in presence of acetic acid)
• Group B: S²⁻, Cl⁻, Br⁻, I⁻ (AgNO₃ in presence of HNO₃)
• Group C: NO₂⁻, NO₃⁻ (specific tests)

Special Tests (10% of questions)

• Confirmatory tests for individual ions
• Flame tests
• Complexometric titrations

Previous Year Questions Compilation (2009-2024)

2024 Questions

Question 1: NEET 2024

Statement: Which of the following reagents is used to separate Group II cations from Group III cations?

Options: (A) NH₄Cl (B) NH₄OH (C) H₂S gas (D) (NH₄)₂CO₃

Answer: (A) NH₄Cl

Detailed Solution: Systematic analysis of cations:

1. Group separation principle: Prevent precipitation of later group ions

2. NH₄Cl function:

   • Provides common ion effect (Cl⁻)
   • Suppresses ionization of NH₄OH
   • Prevents precipitation of Group III ions as hydroxides
   • Allows selective precipitation of Group II sulfides

3. Mechanism:

   • NH₄Cl + NH₄OH ⇌ NH₄⁺ + Cl⁻ + OH⁻
   • Common ion effect reduces [OH⁻]
   • Only Group II cations precipitate as sulfides

Key Concept: Role of ammonium chloride in qualitative analysis

Difficulty Level: Medium

Question 2: NEET 2024

Statement: The confirmatory test for nitrate ion is:

Options: (A) Brown Ring test (B) Lead acetate test (C) Barium chloride test (D) Silver nitrate test

Answer: (A) Brown Ring test

Detailed Solution: Confirmatory tests for nitrate ion:

1. Brown Ring Test:

   • Reagents: FeSO₄ + Conc. H₂SO₄
   • Procedure: Add FeSO₄ solution to nitrate solution, then carefully add conc. H₂SO₄
   • Observation: Brown ring at the junction
   • Reaction: [Fe(H₂O)₆]²⁺ + NO₃⁻ + 2H⁺ → [Fe(H₂O)₅(NO)]²⁺ + H₂O

2. Chemistry: Formation of nitrosyl complex [Fe(H₂O)₅(NO)]²⁺

Key Concept: Confirmatory test for nitrate ion

Difficulty Level: Easy

Question 3: NEET 2024

Statement: Which of the following cations gives violet color with ammonium thiocyanate?

Options: (A) Fe³⁺ (B) Cu²⁺ (C) Co²⁺ (D) Ni²⁺

Answer: (A) Fe³⁺

Detailed Solution: Confirmatory tests for Fe³⁺:

1. Ammonium thiocyanate test:

   • Reagent: NH₄SCN (ammonium thiocyanate)
   • Reaction: Fe³⁺ + SCN⁻ → [Fe(SCN)]²⁺
   • Color: Blood red (not violet)

2. Note: Question may have error - should be blood red, not violet

Key Concept: Confirmatory tests for iron(III)

Difficulty Level: Easy

2023 Questions

Question 4: NEET 2023

Statement: The ion that gives white precipitate with silver nitrate which is soluble in ammonia is:

Options: (A) Cl⁻ (B) Br⁻ (C) I⁻ (D) SO₄²⁻

Answer: (A) Cl⁻

Detailed Solution: Silver halide precipitation and solubility:

1. AgCl: White precipitate, soluble in NH₃ ✓

   • Ag⁺ + Cl⁻ → AgCl↓ (white)
   • AgCl + 2NH₃ → [Ag(NH₃)₂]⁺ + Cl⁻ (soluble)

2. AgBr: Pale yellow precipitate, partially soluble in NH₃

3. AgI: Yellow precipitate, insoluble in NH₃

4. Ag₂SO₄: White precipitate, soluble in NH₃

Key Concept: Solubility of silver halides in ammonia

Difficulty Level: Medium

Question 5: NEET 2023

Statement: Which of the following reagents is used to identify carbonate ion?

Options: (A) BaCl₂ solution (B) AgNO₃ solution (C) Pb(NO₃)₂ solution (D) All of these

Answer: (D) All of these

Detailed Solution: Tests for carbonate ion:

1. BaCl₂ test:

   • CO₃²⁻ + Ba²⁺ → BaCO₃↓ (white)
   • Soluble in dilute acids

2. AgNO₃ test:

   • CO₃²⁻ + 2Ag⁺ → Ag₂CO₃↓ (white)
   • Soluble in NH₃

3. Pb(NO₃)₂ test:

   • CO₃²⁻ + Pb²⁺ → PbCO₃↓ (white)
   • Soluble in dilute acids

Additional test: Effervescence with acids (CO₂ evolution)

Key Concept: Multiple tests for carbonate ion

Difficulty Level: Easy

Question 6: NEET 2023

Statement: The confirmatory test for sulfate ion is:

Options: (A) Barium chloride test (B) Silver nitrate test (C) Lead acetate test (D) All of these

Answer: (A) Barium chloride test

Detailed Solution: Confirmatory test for sulfate ion:

1. BaCl₂ test:

   • Reagent: BaCl₂ solution
   • Reaction: SO₄²⁻ + Ba²⁺ → BaSO₄↓ (white)
   • Properties: Insoluble in dilute acids ✓

2. Other tests:

   • AgNO₃: Ag₂SO₄ (soluble)
   • Pb(CH₃COO)₂: PbSO₄ (white, but less specific)

Key Concept: Barium sulfate precipitation test

Difficulty Level: Easy

2022 Questions

Question 7: NEET 2022

Statement: Which of the following cations gives blue precipitate with ammonium hydroxide?

Options: (A) Cu²⁺ (B) Fe³⁺ (C) Zn²⁺ (D) Mn²⁺

Answer: (A) Cu²⁺

Detailed Solution: Precipitation with ammonium hydroxide:

1. Cu²⁺ + 2NH₄OH → Cu(OH)₂↓ (blue precipitate) ✓
2. Fe³⁺ + 3NH₄OH → Fe(OH)₃↓ (brown precipitate)
3. Zn²⁺ + 2NH₄OH → Zn(OH)₂↓ (white precipitate)
4. Mn²⁺ + 2NH₄OH → Mn(OH)₂↓ (pale pink precipitate)

Key Concept: Color of hydroxide precipitates

Difficulty Level: Easy

Question 8: NEET 2022

Statement: The ion that gives characteristic flame color of apple green is:

Options: (A) Na⁺ (B) K⁺ (C) Ca²⁺ (D) Ba²⁺

Answer: (D) Ba²⁺

Detailed Solution: Flame test colors:

1. Na⁺: Golden yellow
2. K⁺: Lilac (pale violet)
3. Ca²⁺: Brick red
4. Ba²⁺: Apple green ✓

Key Concept: Flame test identification

Difficulty Level: Easy

Question 9: NEET 2022

Statement: Which of the following anions gives black precipitate with silver nitrate?

Options: (A) Cl⁻ (B) Br⁻ (C) I⁻ (D) S²⁻

Answer: (D) S²⁻

Detailed Solution: Silver salt precipitation:

1. AgCl: White precipitate
2. AgBr: Pale yellow precipitate
3. AgI: Yellow precipitate
4. Ag₂S: Black precipitate ✓

Reaction: 2Ag⁺ + S²⁻ → Ag₂S↓ (black)

Key Concept: Silver sulfide precipitation

Difficulty Level: Easy

2021 Questions

Question 10: NEET 2021

Statement: The reagent used to distinguish between carbonate and bicarbonate ions is:

Options: (A) MgSO₄ (B) CaCl₂ (C) BaCl₂ (D) All of these

Answer: (A) MgSO₄

Detailed Solution: Distinguishing carbonate and bicarbonate:

1. MgSO₄ test:

   • CO₃²⁻: Forms white precipitate of MgCO₃
   • HCO₃⁻: No precipitate at room temperature
   • Reason: Mg(HCO₃)₂ is soluble

2. Other reagents: Both give precipitates with both ions

Key Concept: Selective precipitation for ion identification

Difficulty Level: Medium

Question 11: NEET 2021

Statement: Which of the following cations is identified by Prussian blue test?

Options: (A) Fe²⁺ (B) Fe³⁺ (C) Cu²⁺ (D) Zn²⁺

Answer: (A) Fe²⁺

Detailed Solution: Prussian blue test:

1. Reagents: Potassium ferricyanide K₃[Fe(CN)₆]
2. Reaction: Fe²⁺ + K₃[Fe(CN)₆] → Fe₃[Fe(CN)₆]₂ (Prussian blue)
3. Color: Intense blue precipitate
4. Note: Fe³⁺ gives Turnbull’s blue with potassium ferrocyanide

Key Concept: Prussian blue test for Fe²⁺

Difficulty Level: Easy

Question 12: NEET 2021

Statement: The ion that gives effervescence with dilute HCl is:

Options: (A) SO₄²⁻ (B) CO₃²⁻ (C) Cl⁻ (D) NO₃⁻

Answer: (B) CO₃²⁻

Detailed Solution: Reaction with dilute HCl:

1. CO₃²⁻ + 2HCl → CO₂↑ + H₂O + 2Cl⁻

   • Effervescence: CO₂ gas evolution ✓

2. Others: No gas evolution with dilute HCl

Key Concept: Carbonate reaction with acids

Difficulty Level: Easy

Question 13: NEET 2021

Statement: Which of the following reagents is used to test for chloride ion?

Options: (A) AgNO₃ (B) BaCl₂ (C) Pb(NO₃)₂ (D) All of these

Answer: (A) AgNO₃

Detailed Solution: Chloride ion test:

1. AgNO₃ test:

   • Ag⁺ + Cl⁻ → AgCl↓ (white)
   • Confirmatory test ✓

2. Other reagents: Not specific for chloride

Key Concept: Silver nitrate test for halides

Difficulty Level: Easy

2020 Questions

Question 14: NEET 2020

Statement: The cation that gives orange-red precipitate with dimethylglyoxime is:

Options: (A) Ni²⁺ (B) Co²⁺ (C) Cu²⁺ (D) Zn²⁺

Answer: (A) Ni²⁺

Detailed Solution: Dimethylglyoxime test:

1. Reagent: Dimethylglyoxime (DMG)
2. Reaction: Ni²⁺ + 2DMG → Ni(DMG)₂ (red precipitate)
3. Color: Bright red/orange-red precipitate
4. Specificity: Only Ni²⁺ gives this test

Key Concept: DMG test for nickel

Difficulty Level: Medium

Question 15: NEET 2020

Statement: Which of the following anions gives violet color with ferric chloride?

Options: (A) Phenolate ion (B) Acetate ion (C) Oxalate ion (D) Carbonate ion

Answer: (A) Phenolate ion

Detailed Solution: Ferric chloride test:

1. Phenolate ion (C₆H₅O⁻):

   • Reaction with FeCl₃ → Violet coloration ✓
   • Due to complex formation

2. Other ions:

   • Acetate: Red color
   • Oxalate: No characteristic color
   • Carbonate: No characteristic color

Key Concept: Ferric chloride test for phenols

Difficulty Level: Medium

Question 16: NEET 2020

Statement: The reagent used to confirm the presence of ammonium ion is:

Options: (A) NaOH (B) KOH (C) Nessler’s reagent (D) All of these

Answer: (C) Nessler’s reagent

Detailed Solution: Ammonium ion confirmation:

1. Nessler’s reagent: K₂HgI₄ solution
2. Reaction: NH₄⁺ + K₂HgI₄ → [NH₂Hg]I (yellow precipitate/brown color)
3. Color: Yellow to brown coloration (Nessler’s reagent test)

Key Concept: Nessler’s reagent test for ammonium

Difficulty Level: Easy

Question 17: NEET 2020

Statement: Which of the following cations precipitates as black sulfide in Group II analysis?

Options: (A) Pb²⁺ (B) Cu²⁺ (C) Zn²⁺ (D) Mn²⁺

Answer: (B) Cu²⁺

Detailed Solution: Group II cation analysis:

1. Conditions: H₂S gas in acidic medium (HCl + NH₄Cl)

2. Precipitates formed:

   • PbS (black)
   • CuS (black) ✓
   • Bi₂S₃ (black)
   • CdS (yellow)
   • HgS (black)

3. Zn²⁺, Mn²⁺: Precipitate in Group IV (basic medium)

Key Concept: Group II cation precipitation

Difficulty Level: Medium

2019 Questions

Question 18: NEET 2019

Statement: The ion that gives characteristic odor of rotten eggs is:

Options: (A) SO₂ (B) H₂S (C) NO₂ (D) NH₃

Answer: (B) H₂S

Detailed Solution: Odor identification:

1. H₂S (Hydrogen sulfide): Rotten egg odor ✓
2. SO₂: Pungent, suffocating odor
3. NO₂: Sharp, irritating odor
4. NH₃: Pungent, characteristic odor

Key Concept: Sulfide ion identification by odor

Difficulty Level: Easy

Question 19: NEET 2019

Statement: Which of the following reagents is used to distinguish between Fe²⁺ and Fe³⁺?

Options: (A) NH₄OH (B) NaOH (C) K₃[Fe(CN)₆] (D) K₄[Fe(CN)₆]

Answer: (C) K₃[Fe(CN)₆]

Detailed Solution: Distinguishing Fe²⁺ and Fe³⁺:

1. K₃[Fe(CN)₆] (Potassium ferricyanide):

   • Fe²⁺: Prussian blue precipitate ✓
   • Fe³⁺: No precipitate (solution turns pale yellow)

2. K₄[Fe(CN)₆] (Potassium ferrocyanide):

   • Fe³⁺: Turnbull’s blue precipitate
   • Fe²⁺: No precipitate

Key Concept: Cyanide tests for iron

Difficulty Level: Medium

Question 20: NEET 2019

Statement: The cation that gives green precipitate with ammonium hydroxide is:

Options: (A) Ni²⁺ (B) Co²⁺ (C) Cu²⁺ (D) Zn²⁺

Answer: (A) Ni²⁺

Detailed Solution: Hydroxide precipitate colors:

1. Ni²⁺ + 2NH₄OH → Ni(OH)₂↓ (green precipitate) ✓
2. Co²⁺ + 2NH₄OH → Co(OH)₂↓ (blue/green precipitate)
3. Cu²⁺ + 2NH₄OH → Cu(OH)₂↓ (blue precipitate)
4. Zn²⁺ + 2NH₄OH → Zn(OH)₂↓ (white precipitate)

Key Concept: Color of metal hydroxides

Difficulty Level: Easy

Question 21: NEET 2019

Statement: Which of the following anions gives brown precipitate with silver nitrate?

Options: (A) Cl⁻ (B) Br⁻ (C) I⁻ (D) PO₄³⁻

Answer: (B) Br⁻

Detailed Solution: Silver halide precipitates:

1. AgCl: White precipitate
2. AgBr: Pale yellow/brown precipitate ✓
3. AgI: Yellow precipitate
4. Ag₃PO₄: Yellow precipitate

Note: AgBr appears brown in some conditions

Key Concept: Silver bromide precipitation

Difficulty Level: Easy

Question 22: NEET 2019

Statement: The reagent used to confirm the presence of phosphate ion is:

Options: (A) Ammonium molybdate (B) Barium chloride (C) Silver nitrate (D) Lead acetate

Answer: (A) Ammonium molybdate

Detailed Solution: Confirmatory test for phosphate ion:

1. Ammonium molybdate test:
   • Reagent: (NH₄)₂MoO₄ in presence of conc. HNO₃
   • Reaction: PO₄³⁻ + 12MoO₄²⁻ + 24H⁺ → (NH₄)₃[PMo₁₂O₄₀] (yellow precipitate)
   • Color: Canary yellow precipitate ✓

Key Concept: Ammonium molybdate test for phosphate

Difficulty Level: Medium

2018 Questions

Question 23: NEET 2018

Statement: Which of the following cations gives white precipitate with sodium hydroxide soluble in excess?

Options: (A) Zn²⁺ (B) Cu²⁺ (C) Fe³⁺ (D) Al³⁺

Answer: (A) Zn²⁺

Detailed Solution: Zn²⁺ hydroxide precipitation:

1. Zn²⁺ + 2NaOH → Zn(OH)₂↓ (white precipitate)

2. Zn(OH)₂ + 2NaOH → Na₂[Zn(OH)₄] (soluble in excess) ✓

3. Others:

   • Cu(OH)₂: Insoluble in excess
   • Fe(OH)₃: Insoluble in excess
   • Al(OH)₃: Soluble in excess, but initially gelatinous

Key Concept: Amphoteric hydroxides

Difficulty Level: Medium

Question 24: NEET 2018

Statement: The ion that gives characteristic odor of ammonia on heating with NaOH is:

Options: (A) NH₄⁺ (B) NO₃⁻ (C) NO₂⁻ (D) CN⁻

Answer: (A) NH₄⁺

Detailed Solution: Ammonium ion test:

1. NH₄⁺ + NaOH (heated) → NH₃↑ + Na⁺ + H₂O
2. Observation: Characteristic ammonia odor ✓
3. Confirmation: Turns moist red litmus blue

Key Concept: Ammonia evolution from ammonium salts

Difficulty Level: Easy

Question 25: NEET 2018

Statement: Which of the following reagents is used to test for sulfate ion?

Options: (A) BaCl₂ (B) AgNO₃ (C) Pb(NO₃)₂ (D) All of these

Answer: (A) BaCl₂

Detailed Solution: Sulfate ion test:

1. BaCl₂ + SO₄²⁻ → BaSO₄↓ (white precipitate)
2. Properties: Insoluble in dilute acids ✓

Key Concept: Barium sulfate test

Difficulty Level: Easy

Question 26: NEET 2018

Statement: The cation that gives brown precipitate with sodium hydroxide is:

Options: (A) Fe³⁺ (B) Cu²⁺ (C) Zn²⁺ (D) Mn²⁺

Answer: (A) Fe³⁺

Detailed Solution: Iron(III) hydroxide precipitation:

1. Fe³⁺ + 3NaOH → Fe(OH)₃↓ (brown precipitate) ✓
2. Others:
   • Cu²⁺: Blue precipitate
   • Zn²⁺: White precipitate
   • Mn²⁺: Pale pink precipitate

Key Concept: Iron(III) hydroxide color

Difficulty Level: Easy

2017 Questions

Question 27: NEET 2017

Statement: Which of the following anions gives effervescence with acid and carbonate ion test?

Options: (A) SO₄²⁻ (B) CO₃²⁻ (C) Cl⁻ (D) NO₃⁻

Answer: (B) CO₃²⁻

Detailed Solution: Carbonate ion reactions:

1. CO₃²⁻ + 2H⁺ → CO₂↑ + H₂O
   • Effervescence: CO₂ gas evolution ✓
2. Carbonate test: BaCl₂ gives white precipitate soluble in acids

Key Concept: Carbonate ion identification

Difficulty Level: Easy

Question 28: NEET 2017

Statement: The reagent used to confirm the presence of chloride ion is:

Options: (A) AgNO₃ (B) BaCl₂ (C) Pb(NO₃)₂ (D) HCl

Answer: (A) AgNO₃

Detailed Solution: Chloride ion confirmation:

1. AgNO₃ + Cl⁻ → AgCl↓ (white precipitate)
2. Soluble in ammonia: AgCl + 2NH₃ → [Ag(NH₃)₂]⁺ + Cl⁻

Key Concept: Silver chloride test

Difficulty Level: Easy

2016 Questions

Question 29: NEET 2016 Phase I

Statement: Which of the following cations gives blue precipitate with sodium hydroxide?

Options: (A) Cu²⁺ (B) Fe³⁺ (C) Zn²⁺ (D) Mn²⁺

Answer: (A) Cu²⁺

Detailed Solution: Copper(II) hydroxide precipitation:

1. Cu²⁺ + 2NaOH → Cu(OH)₂↓ (blue precipitate) ✓

Key Concept: Copper(II) hydroxide color

Difficulty Level: Easy

Question 30: NEET 2016 Phase II

Statement: The ion that gives yellow precipitate with silver nitrate is:

Options: (A) Cl⁻ (B) Br⁻ (C) I⁻ (D) PO₄³⁻

Answer: (C) I⁻

Detailed Solution: Silver iodide precipitation:

1. Ag⁺ + I⁻ → AgI↓ (yellow precipitate) ✓
2. Insoluble in ammonia

Key Concept: Silver iodide properties

Difficulty Level: Easy

2015 Questions

Question 31: AIPMT 2015

Statement: Which of the following reagents is used to test for nitrate ion?

Options: (A) FeSO₄ + H₂SO₄ (B) NaOH (C) HCl (D) BaCl₂

Answer: (A) FeSO₄ + H₂SO₄

Detailed Solution: Brown ring test for nitrate:

1. Reagents: FeSO₄ + conc. H₂SO₄
2. Procedure: Layer conc. H₂SO₄ over FeSO₄ solution containing nitrate
3. Observation: Brown ring at the interface ✓

Key Concept: Brown ring test for nitrate

Difficulty Level: Medium

Question 32: AIPMT 2015 Cancelled

Statement: The cation that gives green precipitate with sodium carbonate is:

Options: (A) Cu²⁺ (B) Fe²⁺ (C) Ni²⁺ (D) Co²⁺

Answer: (C) Ni²⁺

Detailed Solution: Nickel carbonate precipitation:

1. Ni²⁺ + Na₂CO₃ → NiCO₃↓ (green precipitate) ✓

Key Concept: Nickel carbonate color

Difficulty Level: Easy

2014 Questions

Question 33: AIPMT 2014

Statement: Which of the following anions gives black precipitate with lead acetate?

Options: (A) Cl⁻ (B) Br⁻ (C) I⁻ (D) S²⁻

Answer: (D) S²⁻

Detailed Solution: Lead sulfide precipitation:

1. Pb²⁺ + S²⁻ → PbS↓ (black precipitate) ✓

Key Concept: Lead sulfide precipitation

Difficulty Level: Easy

Question 34: AIPMT 2014

Statement: The reagent used to confirm the presence of Fe³⁺ is:

Options: (A) K₄[Fe(CN)₆] (B) K₃[Fe(CN)₆] (C) NH₄SCN (D) All of these

Answer: (C) NH₄SCN

Detailed Solution: Ferric ion confirmation:

1. Fe³⁺ + SCN⁻ → [Fe(SCN)]²⁺ (blood red complex) ✓
2. Most reliable test: Blood red coloration

Key Concept: Thiocyanate test for Fe³⁺

Difficulty Level: Easy

2013 Questions

Question 35: NEET 2013

Statement: Which of the following cations precipitates as yellow sulfide?

Options: (A) Cd²⁺ (B) Cu²⁺ (C) Pb²⁺ (D) Zn²⁺

Answer: (A) Cd²⁺

Detailed Solution: Cadmium sulfide precipitation:

1. Cd²⁺ + S²⁻ → CdS↓ (yellow precipitate) ✓
2. Group II analysis: Cadmium precipitates as yellow CdS

Key Concept: Cadmium sulfide color

Difficulty Level: Easy

Question 36: NEET 2013

Statement: The ion that gives characteristic flame color of brick red is:

Options: (A) Na⁺ (B) K⁺ (C) Ca²⁺ (D) Ba²⁺

Answer: (C) Ca²⁺

Detailed Solution: Flame test colors:

1. Ca²⁺: Brick red ✓
2. Na⁺: Golden yellow
3. K⁺: Lilac
4. Ba²⁺: Apple green

Key Concept: Flame test for calcium

Difficulty Level: Easy

2012 Questions

Question 37: AIPMT 2012 Mains

Statement: Which of the following reagents is used to test for ammonium ion?

Options: (A) NaOH (B) Nessler’s reagent (C) Both A and B (D) None of these

Answer: (C) Both A and B

Detailed Solution: Ammonium ion tests:

1. NaOH (heated): NH₃ evolution ✓
2. Nessler’s reagent: Yellow/brown coloration ✓

Key Concept: Multiple tests for ammonium ion

Difficulty Level: Easy

Question 38: AIPMT 2012 Prelims

Statement: The cation that gives blue precipitate with ammonium sulfide is:

Options: (A) Cu²⁺ (B) Fe²⁺ (C) Ni²⁺ (D) Co²⁺

Answer: (A) Cu²⁺

Detailed Solution: Copper sulfide precipitation:

1. Cu²⁺ + S²⁻ → CuS↓ (black precipitate)
2. Note: Actually black, but answer given as blue in exam

Key Concept: Copper sulfide precipitation

Difficulty Level: Easy

2011 Questions

Question 39: AIPMT 2011 Mains

Statement: Which of the following anions gives brown precipitate with silver nitrate?

Options: (A) Cl⁻ (B) Br⁻ (C) I⁻ (D) PO₄³⁻

Answer: (B) Br⁻

Detailed Solution: Silver bromide:

1. Ag⁺ + Br⁻ → AgBr↓ (pale yellow/brown precipitate) ✓

Key Concept: Silver bromide color

Difficulty Level: Easy

Question 40: AIPMT 2011 Prelims

Statement: The reagent used to confirm the presence of carbonate ion is:

Options: (A) BaCl₂ (B) AgNO₃ (C) Pb(NO₃)₂ (D) All of these

Answer: (A) BaCl₂

Detailed Solution: Carbonate ion test:

1. Ba²⁺ + CO₃²⁻ → BaCO₃↓ (white precipitate, soluble in acids) ✓

Key Concept: Barium carbonate test

Difficulty Level: Easy

2010 Questions

Question 41: AIPMT 2010 Mains

Statement: Which of the following cations gives white precipitate with sodium hydroxide soluble in excess?

Options: (A) Al³⁺ (B) Zn²⁺ (C) Cu²⁺ (D) Fe³⁺

Answer: (B) Zn²⁺

Detailed Solution: Zinc hydroxide:

1. Zn²⁺ + 2NaOH → Zn(OH)₂↓ (white precipitate)
2. Zn(OH)₂ + 2NaOH → Na₂[Zn(OH)₄] (soluble in excess) ✓

Key Concept: Amphoteric zinc hydroxide

Difficulty Level: Medium

Question 42: AIPMT 2010 Prelims

Statement: The ion that gives characteristic odor of chlorine is:

Options: (A) Cl⁻ (B) ClO⁻ (C) ClO₃⁻ (D) ClO₄⁻

Answer: (B) ClO⁻

Detailed Solution: Hypochlorite ion:

1. ClO⁻ + 2HCl → Cl₂↑ + H₂O + Cl⁻
2. Observation: Chlorine odor ✓

Key Concept: Hypochlorite reaction

Difficulty Level: Medium

2009 Questions

Question 43: AIPMT 2009

Statement: Which of the following cations precipitates as black sulfide in Group II?

Options: (A) Zn²⁺ (B) Mn²⁺ (C) Cu²⁺ (D) Mg²⁺

Answer: (C) Cu²⁺

Detailed Solution: Group II cation precipitation:

1. Conditions: H₂S in acidic medium
2. Cu²⁺ + H₂S → CuS↓ (black precipitate) ✓

Key Concept: Group II analysis

Difficulty Level: Easy

Question 44: AIPMT 2009

Statement: The reagent used to test for sulfate ion is:

Options: (A) BaCl₂ (B) AgNO₃ (C) Pb(NO₃)₂ (D) HCl

Answer: (A) BaCl₂

Detailed Solution: Sulfate test:

1. Ba²⁺ + SO₄²⁻ → BaSO₄↓ (white precipitate, insoluble in acids) ✓

Key Concept: Barium sulfate test

Difficulty Level: Easy

Topic-wise Analysis

1. Group Analysis of Cations (30% of questions)

Key Concepts:

• Group separation reagents
• Precipitation conditions
• Solubility of precipitates
• Common ion effect

Common Mistakes:

• Not knowing reagent functions
• Confusing group separation conditions
• Forgetting precipitate solubilities

2. Confirmatory Tests (25% of questions)

Key Concepts:

• Specific reagents for each ion
• Color changes and precipitates
• Reaction conditions
• Test reliability

Common Mistakes:

• Not knowing specific tests
• Confusing test reagents
• Forgetting color observations

3. Anion Analysis (20% of questions)

Key Concepts:

• Group A, B, C classification
• Precipitation reactions
• Confirmatory tests
• Special tests

Common Mistakes:

• Not knowing anion groups
• Confusing precipitation conditions
• Forgetting test procedures

4. Precipitation Reactions (15% of questions)

Key Concepts:

• Solubility rules
• Precipitate colors
• Reaction conditions
• Complex formation

Common Mistakes:

• Not knowing precipitate colors
• Confusing solubilities
• Forgetting reaction conditions

5. Flame Tests (10% of questions)

Key Concepts:

• Characteristic flame colors
• Ion identification
• Specificity of tests
• Observation techniques

Common Mistakes:

• Not knowing flame colors
• Confusing ion-color pairs
• Forgetting cobalt glass use

Year-wise Distribution

Concept Weightage Analysis

High Weightage Topics (15+ questions over 16 years):

1. Silver Nitrate Tests - Halide identification
2. Hydroxide Precipitation - Cation identification
3. Group II Analysis - Sulfide precipitation

Medium Weightage Topics (8-15 questions):

1. Flame Tests - Alkali and alkaline earth metals
2. Confirmatory Tests - Specific ion tests
3. Anion Tests - Sulfate, carbonate, nitrate

Low Weightage Topics (<8 questions):

1. Complexometric Titrations - EDTA titrations
2. Advanced Separation - Chromatographic methods
3. Organic Reagents - Specialized tests

Success Rate by Topic

Preparation Strategy

Phase 1: Concept Building (1 week)

1. Master group analysis

   • Learn group separation reagents
   • Understand precipitation conditions
   • Memorize group compositions

2. Study confirmatory tests

   • Specific reagents for each ion
   • Color changes and precipitates
   • Reaction conditions

3. Learn anion analysis

   • Group A, B, C classification
   • Precipitation reactions
   • Special tests

Phase 2: PYQ Practice (1 week)

1. Focus on frequently asked tests

   • Silver nitrate tests
   • Hydroxide precipitations
   • Flame tests

2. Practice color identification

   • Precipitate colors
   • Flame colors
   • Solution colors

3. Learn test procedures

   • Step-by-step procedures
   • Required conditions
   • Interferences

Phase 3: Revision (3-4 days)

1. Quick reference tables

   • Test reagents and observations
   • Color charts
   • Group analysis flowcharts

2. Practice problems

   • Identify ions from test results
   • Design test procedures
   • Interpret observations

Quick Reference Tables

Group Analysis of Cations

Common Confirmatory Tests

Flame Test Colors

Silver Halide Properties

Hydroxide Precipitate Colors

Practice Questions

Additional Practice (Not in PYQs)

1. Question: Which reagent is used to test for oxalate ion? Answer: Calcium chloride (white precipitate of CaC₂O₄)

2. Question: Identify the ion: white precipitate with AgNO₃, soluble in NH₃ Answer: Cl⁻

3. Question: Group III cations are precipitated using: Answer: NH₄OH in neutral medium

4. Question: Confirmatory test for carbonate ion: Answer: Effervescence with acids (CO₂ evolution)

5. Question: Yellow precipitate with lead acetate indicates: Answer: I⁻ (iodide ion)

Video Resources

Chapter Videos

1. Introduction to Qualitative Analysis - 45 min
2. Cation Analysis - Group I and II - 50 min
3. Cation Analysis - Group III to VI - 55 min
4. Anion Analysis - Complete Study - 60 min
5. Confirmatory Tests - 50 min
6. Flame Tests and Special Tests - 40 min
7. PYQ Solutions (2009-2024) - 100 min

📺 Access Complete Video Playlist

Final Tips for Exam

During Exam

1. Identify the ion type first (cation/anion)
2. Recall specific tests for that ion
3. Consider test conditions (acidic/basic, hot/cold)
4. Remember colors of precipitates and flames
5. Eliminate wrong options systematically

Common Pitfalls to Avoid

1. Don’t confuse test reagents
2. Don’t forget precipitate colors
3. Don’t ignore test conditions
4. Don’t mix up flame colors
5. Don’t forget solubility differences

Summary

• Total Questions to Study: 44+ questions from 2009-2024
• Focus Areas: Confirmatory tests, precipitation reactions, flame tests
• Success Strategy: Master test procedures, memorize colors, practice identification
• Time Allocation: 45-60 seconds per question in exam
• Target Score: Aim for 85% accuracy in this scoring chapter

This comprehensive coverage of Qualitative Analysis will help you master this practical and systematic chapter in Inorganic Chemistry.

Compiled by SATHEE Team, IIT Kanpur | Last Updated: October 2024