top of page
Search

Salt Analysis | Class XII | CBSE, ISC and Other State Board

Updated: Dec 21, 2025

AMMONIUM CARBONATE - (NH4)2CO3

AIM

To analyze the given inorganic salt for the presence of one anion and one cation through systematic qualitative analysis.

MATERIAL REQUIRED

  • Apparatus: Test tubes, test tube holder, glass rod, delivery tube, Bunsen burner, watch glass, and filter paper.

  • Reagents: Dilute Hydrochloric acid (HCl), Lime water Ca(OH)2, Sodium hydroxide (NaOH), Nessler’s reagent (K2HgI4), and Concentrated Nitric acid (HNO3).

PRELIMINARY TESTS

SYSTEMATIC ANALYSIS (TABLE)

IDENTIFICATION OF ANION (Acid Radical)

Experiment

Observation

Inference

Dilute HCl Test: Take a pinch of salt and add 1–2 ml of dil. HCl.

Brisk effervescence with evolution of a colourless, odourless gas.

May be Carbonate (CO3–2)

Confirmatory Test (Lime Water): Pass the evolved gas through lime water.

Lime water turns milky.

Carbonate (CO3–2) confirmed.

Prolonged Passage: Continue passing the gas through milky lime water.

Milkiness disappears (solution becomes clear).

Carbonate (CO3–2) confirmed.

IDENTIFICATION OF CATION (Basic Radical)

Experiment

Observation

Inference

Zero Group Analysis: Heat a pinch of salt with NaOH solution.

Evolution of a gas with a pungent smell (Ammonia).

May be Zero group (NH4+).

Glass Rod Test: Bring a glass rod dipped in Conc. HCl near the mouth of the test tube.

Dense white fumes are produced.

Presence of NH4+

Nessler’s Reagent Test: Pass the gas into or add Nessler’s reagent to the salt solution.

Brown precipitate or coloration is formed.

Ammonium (NH4+) confirmed.

RESULT

The given inorganic salt contains:

  • Anion: Carbonate (CO3–2)

  • Cation: Ammonium (NH4+)

  • The salt is: Ammonium Carbonate [(NH4)2CO3]

PRECAUTIONS

  1. Handle concentrated acids and Nessler’s reagent with extreme care.

  2. Do not inhale the gases directly; waft them gently toward your nose.

  3. When testing for CO2 with lime water, ensures the delivery tube does not dip into the reaction mixture, only the lime water.

  4. Use a small amount of salt for PRELIMINARY TESTS to avoid vigorous uncontrolled reactions.

CHEMICAL EQUATIONS INVOLVED

1. Tests for Carbonate (CO3–2)

  • Reaction with HCl:

(NH4)2CO3 + 2HCl → 2NH4Cl + H2O + CO2 ↑

  • Lime Water Test:

Ca(OH)2 + CO2 → CaCO3 ↓(White milkiness) + H2O

  • Excess CO2:

CaCO3 + H2O + CO2 → Ca(HCO3)2 (Soluble)

2. Tests for Ammonium (NH4+)

  • Reaction with NaOH:

(NH4)2CO3 + 2NaOH → Na2CO3 + 2H2O + 2NH3 ↑

  • Formation of White Fumes:

NH3 + HCl → NH4Cl (White fumes)

  • Nessler’s Reagent Reaction:

2K2[HgI4] + NH3 + 3KOH → [HgO.Hg(NH2)I] ↓(Brown ppt) + 7KI + 2H2O

(The brown precipitate is called Iodide of Millon's base)


 AMMONIUM CHLORIDE - NH4Cl

AIM

To identify the acid radical (Anion) and basic radical (Cation) present in the given salt sample.

MATERIALS REQUIRED

  • Salt Sample

  • Reagents: Dilute H2SO4, Concentrated H2SO4, Silver Nitrate (AgNO3) solution, Sodium Hydroxide (NaOH), Nessler’s Reagent (K2HgI4), Manganese dioxide (MnO2).

  • Apparatus: Test tubes, Test tube holder, Glass rod, Bunsen burner, Filter paper.

PRELIMINARY TESTS

Test

Observation

Inference

Colour

White Crystalline

Absence of Cu+2, Fe+2, Fe+3, Co+2, Ni+2, Mn+2

Odour

Odourless

Absence of S–2, CH3COO–, NH4+ (in cold)

Solubility

Soluble in water

Water–soluble salt

Flame Test

No characteristic flame

Absence of Ca+2, Sr+2, Ba+2, Cu+2

SYSTEMATIC ANALYSIS (TABLE)

ANALYSIS OF ANION (Acidic Radical)

Experiment

Observation

Inference

Preliminary Test: Small amount of salt + Conc. H2SO4.

Colorless, pungent–smelling gas. Gives white fumes with NH4OH.

May be Chloride (Cl–).

MnO2 Test: Salt + Conc. H2SO4 + pinch of MnO2 and heat.

Evolution of greenish–yellow gas (Cl2).

Chloride (Cl–) confirmed.

Silver Nitrate Test: Salt solution + dil. HNO3 + AgNO3 solution.

A curdy white precipitate is formed, soluble in NH4OH.

Chloride (Cl–) confirmed.

ANALYSIS OF CATION (Basic Radical)

Experiment

Observation

Inference

Zero Group Analysis: Salt + NaOH solution and heat.

Evolution of gas with a pungent ammonia smell.

May be Ammonium (NH4+).

Glass Rod Test: Bring a glass rod dipped in Conc. HCl near the mouth of the test tube.

Dense white fumes are observed.

Ammonium (NH4+) confirmed.

Nessler’s Reagent Test: Pass the gas through or add Nessler's Reagent to the salt extract.

Brown precipitate or coloration is formed.

Ammonium (NH4+) confirmed.

RESULT

The given salt contains:

  • Anion: Chloride (Cl–)

  • Cation: Ammonium (NH4+)

  • Salt: Ammonium Chloride (NH4Cl)

PRECAUTIONS

  1. Handle Concentrated H2SO4 with extreme care.

  2. Do not inhale the gases directly; waft the smell toward your nose.

  3. When heating a test tube, never point the mouth of the tube toward yourself or others.

  4. Use only a small amount of salt for analysis to get clear results.

CHEMICAL EQUATIONS

For Anion (Cl–):

  1. Reaction with Conc. H2SO4:

NH4Cl + H2SO4 → NH4HSO4 + HCl ↑

  1. Silver Nitrate Test:

NaCl + AgNO3 → AgCl ↓(White ppt) + NaNO3

AgCl + 2NH4OH → [Ag(NH3)2]Cl (Soluble complex) + 2H2O

For Cation (NH4+):

  1. Reaction with NaOH:

NH4Cl + NaOH → NaCl + H2O + NH3 ↑

  1. Nessler’s Reagent Test:

2K2[HgI4] + NH3 + 3KOH → [HgO.Hg(NH2)]I ↓(Brown ppt) + 7KI + 2H2O

(The brown precipitate is known as the Iodide of Millon's base).


 LEAD ACETATE - Pb(CH3COO)2

AIM: To analyze the given salt sample for the presence of one acid radical (anion) and one basic radical (cation).

MATERIALS REQUIRED:

  • Salt sample

  • Test tubes and test–tube holder

  • Glass rod

  • Reagents: Dilute H2SO4, Concentrated H2SO4, Potassium Iodide (KI) solution, Potassium Chromate (K2Cr2O7) solution, Ethanol.

  • Bunsen burner

PRELIMINARY TESTS

Test

Observation

Inference

Colour

White Crystalline

Absence of Cu+2, Fe+2, Fe+3, Co+2, Ni+2, Mn+2

Odour

Vinegar–like (Smell of acetic acid)

May be Acetate CH3COO–

Solubility

Soluble in water

Water–soluble salt.

Flame Test

Dull bluish–white flame

May be Lead Pb+2

ANALYSIS OF ANION (Acidic Radical)

Experiment

Observation

Inference

a) Dilute H2SO4 Test: Take salt and add dil. H2SO4.

No characteristic gas evolved.

Group I anions CO3–2, S–2 absent.

b) Conc. H2SO4 Test: Take salt and add conc. H2SO4, then warm.

Smell of vinegar (acetic acid).

Acetate CH3COO– may be present.

c) Ester Test: Mix salt with ethanol and a few drops of conc. H2SO4. Warm and pour into water.

Pleasant fruity smell.

Acetate CH3COO– Confirmed.

TEST FOR CATIONS (Basic Radicals)



a) Preparation of Original Solution (OS): Dissolve salt in distilled water.

Clear solution obtained.

Used for further tests.

b) Group Separation (Group I): To the OS, add dilute HCl.

White precipitate formed.

Group I Pb+2 present.

c) Confirmatory Test 1: Dissolve the white ppt in hot water. Add KI solution.

Bright yellow precipitate (Lead Iodide) formed.

Lead Pb+2 Confirmed.

d) Confirmatory Test 2: To the hot water solution, add K2Cr2O7 solution.

Yellow precipitate (Lead Chromate) formed.

Lead Pb+2 Confirmed.

RESULT

The given inorganic salt contains:

  • Anion (Acid Radical): Acetate (CH3COO–)

  • Cation (Basic Radical): Lead Pb+2

  • Salt Name: Lead Acetate Pb(CH3COO)2

PRECAUTIONS

  1. Handle concentrated H2SO4 with extreme care.

  2. Lead salts are toxic; wash your hands thoroughly after the experiment.

  3. When checking for odour, do not inhale the gas directly; waft it gently toward your nose.

  4. Always use clean test tubes to avoid contamination and false positive results.

CHEMICAL EQUATIONS INVOLVED

For Acetate (CH3COO– ):

  1. Reaction with Oxalic Acid:

 2CH3COOPb + (COOH)2 → Pb(COO)2 + 2CH3COOH ↑(Vinegar smell)

  1. Esterification Test:

 CH3COOH + C2H5OH → CH3COOC2H5 + H2O

For Lead ( Pb2+ ):

  1. Group Precipitation:

 Pb(CH3COO)2 + 2HCl →  PbCl2 ↓(White ppt) + 2CH3COOH

  1. Potassium Iodide Test:

 PbCl2 + 2KI →  PbI2 ↓(Yellow ppt) + 2KCl

  1. Potassium Chromate Test:

 Pb+2 + K2CrO4 →  PbCrO4 ↓(Yellow ppt) + 2K+ 


 ALUMINIUM SULPHATE - Al2(SO4)3

AIM

To identify the acidic and basic radicals present in the given salt sample (Aluminium Sulphate) through systematic qualitative analysis.

MATERIAL REQUIRED

  • Apparatus: Test tubes, test tube holder, glass rod, delivery tube, Bunsen burner, watch glass.

  • Reagents: Dilute H2SO4, Concentrated H2SO4, Barium Chloride (BaCl2) solution, Lead Acetate solution, Sodium Hydroxide (NaOH), Ammonium Chloride (NH4Cl), Ammonium Hydroxide (NH4OH), Blue litmus paper.

PRELIMINARY TESTS

Test

Observation

Inference

Colour

White crystalline powder

Absence of Cu+2, Fe+2, Fe+3, Co+2, Mn+2, Ni+2

Odour

Odourless

Absence of NH4+, S-2, CH3COO-.

Solubility

Soluble in water

Water-soluble salt.

Flame Test

No characteristic flame colour

Absence of Ca+2, Sr+2, Ba+2, Cu+2

ANALYSIS OF ANION (Acidic Radical)

Experiment

Observation

Inference

1. Dilute H2SO4 Test: Add dil. H2SO4 to a pinch of salt.

No gas evolved.

Group 1 Anions (CO3-2, S-2, NO2-) absent.

2. Conc. H2SO4 Test: Add conc. H2SO4 to a pinch of salt.

No gas evolved.

Group 2 Anions (Cl-, Br-, I-, NO3-) absent.

3. Barium Chloride Test: To the salt solution (Water Extract), add BaCl2 solution.

A white precipitate is formed which is insoluble in conc. HCl.

SO4-2 (Sulphate) indicated.

4. Lead Acetate Test: To the salt solution, add Lead Acetate solution.

A white precipitate is formed.

SO4-2 confirmed.

ANALYSIS OF CATION (Basic Radical)

Experiment

Observation

Inference

1. Group 0 Test: Heat salt with NaOH solution.

No smell of Ammonia.

Zero group (NH4+) absent.

2. Group I Test: Add dil. HCl to salt solution.

No precipitate.

Group I (Pb+2) absent.

3. Group II Test: Pass H2S gas through acidified solution.

No precipitate.

Group II (Cu+2, As+3) absent.

4. Group III Test: To the salt solution, add solid NH4Cl, boil, cool, and then add NH4OH in excess.

A gelatinous white precipitate is formed.

Group III (Al+3) indicated.

5. Confirmatory Test (Lake Test): Dissolve white precipitate in dil. HCl. Add 2 drops of Blue Litmus, then add NH4OH dropwise.

Blue-coloured "lake" (precipitate) floats in a colorless solution.

Al+3 confirmed.

RESULT

The given inorganic salt contains:

  • Acidic Radical: Sulphate (SO4-2)

  • Basic Radical: Aluminium (Al+3)

  • Salt: Aluminium Sulphate [Al2(SO4)3]

PRECAUTIONS

  1. Always use clean and dry test tubes for preliminary tests.

  2. For Group III analysis, ensure NH4Cl is added before NH4OH to suppress the ionization of OH- ions.

  3. Concentrated acids should be handled with extreme care.

  4. The "Lake Test" should be performed carefully; do not add excess litmus solution as it may mask the blue lake.

CHEMICAL EQUATIONS INVOLVED

For Sulphate (SO4-2):

  1. Barium Chloride Test:

Na2SO4 + BaCl2 → BaSO4 ↓(White ppt) + 2NaCl

  1. Lead Acetate Test:

Na2SO4 + (CH3COO)2Pb → PbSO4 ↓(White ppt) + 2CH3COONa

For Aluminium (Al+3):

  1. Group Precipitation:

Al2(SO4)3 + 6NH4OH → 2Al(OH)3 ↓(White ppt) + 3(NH4)2SO4

  1. Lake Test:

Al(OH)3 + 3HCl → AlCl3 + 3H2O

(The Al(OH)3 formed again upon adding NH4OH adsorbs the blue litmus dye to form the "Lake").

 


 MANGANESE SULPHATE - MnSO4

AIM

To identify the anionic (acid radical) and cationic (basic radical) present in the given inorganic salt sample (Manganese Sulphate).

MATERIALS REQUIRED

  • Salt Sample: Manganese Sulphate (MnSO4)

  • Apparatus: Test tubes, test tube holder, glass rod, watch glass, Bunsen burner, delivery tube.

  • Reagents: Dilute H2SO4, Concentrated H2SO4, Barium Chloride (BaCl2) solution, Lead Acetate solution, Sodium Hydroxide (NaOH), Ammonium Chloride (NH4Cl), Ammonium Hydroxide (NH4OH), Hydrogen Sulphide (H2S) gas or Sodium Sulphide, Nitric Acid (HNO3), and Lead Dioxide (PbO2).

PRELIMINARY TESTS

Test

Observation

Inference

1. Colour

Light Pink / Buff coloured

Presence of Mn+2 possible.

2. Odour

Odourless

Absence of NH4+, S-2, and CH3COO-

3. Solubility

Soluble in water

Water-soluble salt

4. Flame Test

No characteristic flame colour

Absence of Cu+2, Ca+2, Sr+2, and Ba+2

ANALYSIS OF ANION (Acid Radical)

Experiment

Observation

Inference

1. Dilute H2SO4 Test: Add dil. H2SO4 to a pinch of salt.

No brisk effervescence or gas evolved.

Absence of CO3-2, S-2, NO2-.

2. Conc. H2SO4 Test: Add conc. H2SO4 to the salt.

No characteristic gas evolved.

Absence of Cl-, Br-, I-, NO3-, C2O4-2

3. Barium Chloride Test: To the aqueous salt solution, add BaCl2 solution.

A thick white precipitate is formed.

Presence of SO4-2

4. Solubility of PPT: Add dil. HCl to the white precipitate.

Precipitate is insoluble in dil. HCl.

Confirms SO4-2

5. Lead Acetate Test: To the aqueous salt solution, add Lead Acetate solution.

A white precipitate is formed.

Confirms SO4-2

ANALYSIS OF CATION (Basic Radical)

Experiment

Observation

Inference

1. Zero Group: Salt + NaOH solution, then heat.

No smell of Ammonia.

Absence of NH4+

2. Group I: Original Solution (O.S.) + dil. HCl.

No precipitate.

Absence of Pb+2

3. Group II: To above solution, pass H2S gas

No precipitate

Absence of Cu+2, As+3

4. Group III: O.S. + solid NH4Cl + excess NH4OH

No precipitate

Absence of Fe+3, Al+3

5. Group IV: To the Group III solution, pass H2S gas

A flesh-coloured (buff) precipitate is formed

Presence of Mn+2

6. Confirmation (NaOH Test): Dissolve ppt in dil HCl, boil off H2S, then add NaOH

White precipitate formed which turns brown on standing

Confirms Mn+2

RESULT

The given inorganic salt contains:

  • Anion: Sulphate (SO4-2)

  • Cation: Manganese (Mn+2)

  • The Salt is: Manganese Sulphate (MnSO4)

PRECAUTIONS

  1. Use clean and dry test tubes for preliminary tests.

  2. While passing H2S gas, ensure the delivery tube is clean to avoid cross-contamination.

  3. Always use the Original Solution (O.S.) for cation analysis (prepared by dissolving salt in distilled water).

  4. Handle concentrated acids with extreme care.

  5. Boil off H2S gas completely from the solution before proceeding to the next group analysis.

 

CHEMICAL EQUATIONS INVOLVED

Tests for Sulphate (SO4-2):

  1. SO4-2 + BaCl2 →BaSO4 ↓(White ppt) + 2Cl-

  2. SO4-2 + (CH3COO)2Pb → PbSO4 ↓ (White ppt) + 2CH3COO-

Tests for Manganese (Mn2+):

  1. Mn+2 + H2S → NH4OH ↓ (Buff/Flesh ppt) + 2H+

  2. MnS + 2HCl → MnCl2 + H2S \uparrow

  3. MnCl2 + 2NaOH → Mn(OH)2 ↓(White ppt)

  4. 2Mn(OH)2 + O2 (air) → 2MnO(OH)2 ↓ (Brown ppt)

Comments

bottom of page