Qualitative Analysis Of Anions [ Procedure and Theory ]

Our Objective

Our objective is to determine the anion present in the given salt.

The Theory

What is Qualitative Inorganic Analysis?

The qualitative inorganic analysis is a method of analytical chemistry that seeks to find out the elemental composition of inorganic compounds through various reagents. It is mainly focused on detection of ions in an aqueous solution, so the substances in other states need to be converted into an aqueous solution before starting the experiment.

The procedure for detecting ions (cations and anions) in aqueous solutions are called Cation Analysis and Anion Analysis.

Let's discuss the Qualitative Analysis of Anions.

Qualitative Analysis of Anions

Preliminary Tests

Some preliminary tests are done before going to the anion analysis.

(A) Physical Examination: Colour and Smell

The physical examination of the unknown salt involves the study of colour, smell and density. Characteristic smell helps to identify some anions such as acetate, sulphide etc.

(B) Dry Heating Test

This test is performed by heating a small amount of salt in a dry test tube. Quite valuable information can be gathered by carefully performing and noting the observations. On heating, some salts undergo decomposition, thus evolving the gases.

(C) Identification of Anions (Acid Radicals)

The identification of the radicals is first done on the basis of the preliminary tests. The Dry heating test is one of the preliminary tests performed earlier which may give some important information about the acid radical present. The other preliminary tests are based on the fact that:

• CO32-, S2-, NO2- and SO32- react with dil. H2SO4 to give out CO2, H2S, NO2 and SO2 gases respectively. These gases on identification indicate the nature of the anion present in the salt.
• Cl-,Br-,I-,NO3- and C2O42- and CH3COO- react with conc. H2SO4 but not with dil. H2SO4 to produce characteristic gases.
• SO42- and PO43- react neither with dil H2SO4 nor with conc. H2SO4. These are, therefore, identified by individual tests.

Thus, these anions may be identified by performing the following tests below:

1) Dil. H2SO4 Tests

Treat a pinch of the salt with dil. H2SO4 and identify the gas evolved.

Chemical Reactions Involved in Dil.H2SO4 Test:

Dilute H2SO4 decomposes carbonates, sulphides, sulphites and nitrites in cold to give gases. These gases on identification indicate the nature of the anion present in the salt.

(a) Carbonate: On treating the solid carbonate, CO2 is given off in the cold with brisk effervescence.

(b) Sulphide: Sulphides when treated with dil. H2SO4 give H2S gas.

(c) Sulphite: On heating solid sulphite with dil.H2SO4, SO2 gas is evolved

(d) Nitrite: On treating solid nitrite with dil. H2SO4, nitric oxide (NO) gas is evolved which readly gives brown fumes of  NO2 with the oxygen of the air.

2) Conc. H2SO4 Test

If no action takes place with dil. H2SO4, warm a pinch of the salt with conc. H2SO4 and identify the gas evolved.

Chemical Reactions Involved in Conc. H2SO4 Test

(a) Chlorides: Chloride salts react with conc. H2SO4 to evolve hydrogen chloride (HCl) gas.

(b) Bromides: Bromide salts react with conc. H2SO4 to evolve bromine gas.

(c) Iodides: Iodide salts react with conc. H2SO4 to evolve vapours of iodine.

(d) Nitrates: Upon reaction with conc.H2SO4 nitrates evolve NO2 gas. 

(e) Acetates: Acetates react with conc. H2SO4 to produce vapours of acetic acid.

(f) Oxalates: Oxalates salts react with conc. H2SO4 to evolve a mixture of carbon dioxide and carbon monoxide. 

3) Independent Group. (SO42- and PO43-) Test

If the salt does not react with dil H2SO4 as well as with conc. H2SO4 test for SO42-and PO43- by performing their individual tests.

4) Potassium permanganate Test

This test is performed by using dilute sulphuric acid and potassium permanganate as reagents. This test helps in the detection of Cl-, Br-, I- and C2O42-.

Chemical reactions involved in Potassium permanganate test

Wet Tests for Acid Radicals (Anions)

Let us discuss the chemical reactions involved in the confirmation of Anions:

Confirmation of Carbonate (CO32-)

(a) Reaction with di.l HCl

Carbonate on reaction with dil. HCl gives CO2 gas that reacts with lime water to produce a white precipitate of calcium carbonate that turns lime water milky. In case of soluble carbonate, this test is performed with water extract and in case of insoluble carbonates, this test is performed with the solid salt.

(b) Magnesium sulphate test

This test is performed in the case of soluble carbonates only. Soluble carbonates react with the magnesium sulphate solution to form a white precipitate of magnesium carbonate.

Confirmation of Sulphite (SO32-)

(a) Barium chloride test

Sulphites on reaction with barium chloride to form a white precipitate of barium sulphite. Barium sulphite dissolved in dil. HCl with the evolution  of sulphur dioxide gas.

(b) Potassium permanganate test

The colour of potassium permanganate is discharged when it reacts with sulphite. The reaction is given below.

(c) Potassium dichromate test

A green colour is obtained when sulphites react with potassium dichromate solution.

Confirmation of Sulphide (S2-)

(a) Sodium nitroprusside test

Sulphides give a violet or purple colouration with the sodium nitroprusside solution due to the formation of Na4[Fe(CN)5NOS].

(b) Lead acetate test

Sulphides react with lead acetate to form a black precipitate of lead sulphide.

(c) Cadmium carbonate test:

Sulphides react with a suspension of cadmium carbonate to form a yellow precipitate of cadmium sulphide.

Confirmation of Nitrite (NO2-)

(a) Ferrous sulphate test

Nitrites give a dark brown or black colouration in Ferrous sulphate test due to the formation of FeSO4.NO.

(b) Starch - Iodide test

Nitrites react with potassium iodide in the presence of dilute sulphuric acid to liberate iodine. Iodine forms a blue-black complex with starch.

(c) Diphenylamine test

In the presence of nitrites, diphenylamine is oxidised, giving a blue colouration.

Confirmation of Nitrate (NO3-)

(a) Diphenylamine test

In the presence of nitrates, diphenylamine is oxidised, giving a blue colouration.

(b) Copper chips test

In this reaction copper chips reduces nitrates to reddish brown NO2 gas.

(c) Brown-ring test

This test can be performed by adding a solution of iron (II) sulphate to a solution of nitrate, followed by the slow addition of concentrated sulphuric acid, such that the sulphuric acid forms a layer below the aqueous solution. The formation of a brown ring at the junction of two layers indicates the presence of nitrate.

The overall reaction is the reduction of nitrate ion by iron (II) which reduced to iron (I) and formation of a nitrosonium complex where nitric oxide is oxidised to NO+.

Confirmation of Chloride (Cl-)

(a) Silver nitrate test

Chlorides on reaction with silver nitrate solution to form a white precipitate of silver chloride which is soluble in ammonium hydroxide.

(b) Manganese dioxide test

When chloride salts react with manganese dioxide and concentrated sulphuric acid, chlorine gas is liberated.

(c) Chromyl chloride test

When chloride salts react with potassium dichromate and conc. sulphuric acid red fumes of chromyl chloride is formed which reacts with sodium hydroxide to form yellow solution of sodium chromate. Sodium chromate reacts with lead acetate in presence of dil. acetic acid to form yellow precipitate of lead chromate.

Confirmation of Bromide (Br-)

(a) Silver nitrate test

Bromides on reaction with silver nitrate solution forms a pale yellow precipitate of silver bromide which is sparingly soluble in ammonium hydroxide.

(b) Manganese dioxide test

When bromide salts react with manganese dioxide and concentrated sulphuric acid, bromine gas is liberated.

(c) Chlorine water test

Bromine liberated in this test being soluble in carbon disulphide imparts an orange colour to the carbon disulphide layer.

Note: Carbon tetrachloride, cyclohexane, chloroform etc can be used instead of carbon disulphide.

Confirmation of Iodide (I-)

(a) Silver nitrate test

Iodides on reaction with silver nitrate solution forms an yellow precipitate of silver iodide which is insoluble in ammonium hydroxide.

(b) Manganese dioxide test:

When iodide salts react with manganese dioxide and concentrated sulphuric acid, iodine gas is liberated.

(c) Chlorine water test

Iodine liberated in this test being soluble in carbon disulphide imparts a violet colour to the carbon disulphide layer.

Note: Carbon tetrachloride, cyclohexane, chloroform etc can be used instead of carbon disulphide.

Confirmation of Acetate (CH3COO-)

(a) Oxalic acid test

Oxalic acid reacts with acetate salt to form acetic acid which has a characteristic vinegar like smell.

(b) Ester test

Acetate salts react with conc. sulphuric acid and ethyl alcohol to form the ester, ethyl acetate which has a fruity smell.

(c) Ferric chloride test

The reaction takes place in the ferric chloride test is given by the following equations.

Confirmation of Oxalate (C2O42-)

(a) Calcium chloride test

Oxalate salts react with calcium chloride to form white precipitate of calcium oxalate.

(b) Potassium permanganate test

In this test, the pink colour of potassium permanganate is decolourised with the evolution of carbon dioxide gas.

Confirmation of Sulphate (SO42-)

(a) Barium chloride test

Sulphates react with barium chloride to form white precipitate of barium sulphate.

(b) Match stick test

Violet streaks are produced during this test.

(c) Lead acetate test

Sulphates react with lead acetate to form white precipitate of lead sulphate.

Confirmation of Phosphate (PO43-)

(a) Ammonium molybdate test

Phosphate salts react with ammonium molybdate solution to form a deep yellow precipitate of ammonium phosphate molybdate. The chemical reaction is as follows:

(b) Magnesia mixture test

Phosphate salts react with magnesia mixture to form white precipitate of magnesium ammonium phosphate.

Note: To prepare magnesia mixture, add solid NH4Cl to magnesium chloride solution. Boil, cool and add NH4OH till a strong smell of ammonia ia obtained.

Learning Outcomes:

• Students understand different types of anions.
• Students understand various tests to identify the anion present in a given salt.
• Students understand the chemical reactions and their balanced equations that takes place during each test.
• Students acquire the skill to perform the experiment in the real lab once they understand different steps in the procedure.

Real Lab Procedure

Prelimimatry Tests

Physical Examination of the Salt

Experiment	Observation	Inference
Smell: Add a drop of water to a pinch of the salt and rub it between the fingers.	Vinegar like smell.	May be CH3COO-
	Smell like that of rotten eggs.	May be S2-
Density	Light fluffy powder.	May be CO32-

Dry Heating Test

Experiment	(a) Colourless and odourless gas
Heat a small quantity of the salt in a dry test tube.	Observation	Inference
	Colourless and odourless gas turns lime water milky.	The gas evolved is CO2. CO32- or C2O42-may be present.
	(b) Colourless gas with odour
	Observation	Inference
	Colourless gas with the smell of rotten eggs, and turns lead acetate paper black.	The gas evolved is H2S. Hydrated S2-may be present.
	Colourless gas with smell of burning sulphur.	The gas evolved is SO2. SO32- may be present.
	Colourless gas with pungent smell, gives white fumes with ammonia.	The gas evolved is HCl. Cl- may be present.
	Colourless gas with the smell of vinegar.	CH3COO- may be present.
	(c) Coloured gases
	Observation	Inference
	Reddish brown fumes that turns ferrous sulphate solution black.	The gas evolved is NO2. NO2- or NO3-may be present.
	Greenish yellow gas that turns the starch iodide paper blue.	Chlorine gas is evolved. Cl- may be present.
	Dark violet vapours that turns starch paper blue.	Iodine vapours are formed. I- may be present.

Dilute Sulphuric Acid Test

Experiment	Observation	Inference
Take a small quantity of the salt in a test tube and add 1-2 ml of dilute sulphuric acid.	Colourless odourless gas with brisk effervescence, turns lime water milky.	The gas evolved is CO2. This may be due to the presence of CO32-.
	Colourless gas with pungent smell, turns acidified potasium dichromate paper or solution green.	The gas evolved is SO2. This may be due to the presence of SO32-.
	Colourless gas with smell like that of rotten eggs, turns lead acetate paper black.	The gas evolved is H2S. This may be due to the presence of S2-.
	Reddish brown gas with pungent smell, turns ferrous sulphate solution black.	The gas evolved is NO2. This may be due to the presence of NO2-.
	No gas is evolved.	CO32-, SO32-, S2-, NO2- etc may be absent.

Concentrated Sulphuric Acid Test

Experiment	Observation	Inference
To a small quantity of salt in a test tube, add 1-2 ml of conc. sulpuric acid.	Colourless gas with pungent smell, form white fumes with aqueous ammonia when a glass rod dipped in aqueous ammonia is shown over the mouth of the test tube.	The gas evolved is HCl. This may be due to the presence of Cl-.
	Reddish brown gas with pungent smell, turns starch paper yellow.	The gas evolved is Br2. This may be due to the presence of Br-.
	Deep violet vapours with pungent smell, turns starch paper blue.	The gas evolved is I2. This may be due to the presence of I-.
	Colourless gas which turns lime water milky.	The gas evolved is CO2. This may be due to the presence of C2O42-.

Independent Group Test

Experiment	Observation	Inference
1) Sulphate: Boil a small amount of salt with dil. HCl in a test tube. Filter the contents, and to the filtrate add few drops of BaCl2solution.	A white precipitate is formed.	The white precipitate is BaSO4. This indicates the presence of SO42-.
2) Phosphate: Boil a small amount of salt with conc. HNO3 in a test tube and add few drops of ammonium molybdate solution.	A yellow precipitate is formed.	The yellow precipitate is ammonium phosphate molybdate. This indicates the presence of PO43-.

Potassium Permanganate Test

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Experiment	Observation	Inference
To a pinch of the salt in a test tube add about 2 ml of dil.H2SO4. Boil off any gas evolved and add little more of dil. H2SO4 and then potassium permanganate dropwise.	Potassium permanganate is decolourised with the evolution of chlorine.	This may be due to the presence of Cl-.
	Potassium permanganate is decolourised with the evolution of bromine.	This may be due to the presence of Br-.
	Potassium permanganate is decolourised with the evolution of iodine.	This may be due to the presence of I-.
To a pinch of the salt in a test tube add about 2 ml of dil.H2SO4. Boil off any gas evolved and add little more of dil. H2SO4 and then potassium permanganate dropwise and warm the test tube.	Potassium permanganate is decolourised with the evolution of CO2.	This may be due to the presence of C2O42-.

Confirmatory Tests

Confirmation of Carbonate, CO32-

Experiment	Observation	Inference
Dil. HCl test:To a portion of the salt solution, add dil HCl. Pass the gas evolved through lime water.	Brisk effervescence and evolution of colourless odourless gases. Lime water turns milky.	The gas evolved is CO2. CO2 reacts with lime water to form white precipitate of CaCO3 which is responsible for the milkness.
Magnesium sulphate test:To a portion of the salt solution, add magnesium sulphate (MgSO4) solution.	Formation of white precipitate.	The white precipitate is MgCO3.

Note:  

• Do not use sodium carbonate extract for performing the tests of carbonate because it contains sodium carbonate.
• Perform magnesium sulphate test only in case of soluble carbonate. 

Confirmation of Sulphite, SO32-

Experiment	Observation	Inference
Barium chloride test: To a portion of the salt solution in a test tube add barium chloride (BaCl2) solution. Add small amount of dil. HCl to the precipitate.	A white precipitate is formed The precipitate dissolves with the evolution of gas.	The white precipitate is barium sulphite. Barium sulphite dissolves in dil. HCl with the liberation of SO2gas.
Potassium dichromate test: To a portion of aqueous solution of salt, add potassium dichromate solution acidified with dil.H2SO4	A green colour is obtained	This confirms the presence of sulphite ion.
Potassium permanganate test: To the aqueous solution of the salt add few drops of potassium permanganate solution acidified with dil. H2SO4.	Colour of KMnO4solution gets discharged.	This confirms the presence of sulphite ion.

Confirmation of Sulphide, S2-

Experiment	Observation	Inference
Sodium nitroprusside test:Take a portion of salt solution in a test tube and add a few drops of sodium nitroprusside solution.	Purple or violet colouration is obtained.	The purple or violet colouration is due to the formation of Na4[Fe(CN)5NOS].
Lead acetate test: To a portion of salt solution add lead acetate solution.	A black precipitate is obtained.	The black precipitate is lead sulphide (PbS).
Cadmium carbonate test: To a portion of aqueous solution of salt, add a suspension of cadmium carbonate in water.	A yellow precipitate is formed.	The yellow precipitate is cadmium sulphide (CdS).

Confirmation of Nitrite, NO2-

Experiment	Observation	Inference
Ferrous sulphate test: Take a portion of aqueous solution, add some dil. acetic acid and ferrous sulphate solution.	A dark brown or black colouration is obtained.	The black colour is due to the formation of FeSO4.NO.
Starch-iodide test: To a portion of aqueous solution add a few drops of dilute H2SO4 and a few drops of potassium iodide solution followed by freshly prepared starch solution.	A blue solution is obtained.	Iodine liberated during the reaction forms a blue-black complex with strach.
Diphenylamine test:To a portion of aqueous solution, add few drops of diphenylamine.	A deep blue colouration is obtained.	In the presence of nitrite diphenylamine gets oxidised, giving a blue colouration.

Confirmation of Nitrate, NO3-

Experiment	Observation
Diphenylamine test: Add a few drops of diphenylalamine to a part of aqueous solution of the salt.	A deep blue colouration is obtained.	In the presence of nitrate diphenylamine gets oxidised, giving a blue colouration.
Copper chip test: Heat a small quantity of the original salt with concentrated sulphuric acid and a few copper chips.	Dark brown fumes of nitrogen dioxide are evolved	The reddish-brown fumes is due to the formation of NO2gas.
Brown Ring test: Add a small quantity of freshly prepared solution of ferrous sulphate to a part of the aqueous solution and then pour concentrated sulphuric acid slowly along the sides of the test tube.	A dark brown ring is formed at the junction of the layers of the acid and the solution.	The brown ring is due to the formation of nitrosonium complex, [Fe(NO)(H2O)5]SO4

Confirmation of Chloride, Cl-

Experiment	Observation	Inference
Silver nitrate test: Acidify a portion of aqueous solution with dil. HNO3. Boil for some time, cool and add AgNO3solution.	A white precipitate is formed which is soluble in ammonium hydroxide.	The white precipitate is silver chloride which dissolved in ammonium hydroxide to form the soluble complex, [Ag(NH3)2]Cl.
Maganese dioxide test:Heat a pinch of the salt with a small quantity of MnO4 and conc. H2SO4.	Evolution of greenish yellow gas having a pungent irritating smell. It turns moist starch-iodide paper blue.	The greenish yellow gas is due to the formation of chlorine gas.
Chromyl chloride test: Mix a small quantity of the salt with a small amount of powdered potassium dichromate. Take the mixture in a test tube and add conc. H2SO4. Heat the test tube and pass the red vapours evolved into the gas detector containing NaOH solution. To the yellow solution thus obtained, add dil. CH3COOH and lead acetate solution.	A yellow precipitate is formed.	The red fumes is due to the formation of chromyl chloride (CrO2Cl2). CrO2Cl2 reacts with NaOH to form yellow solution of sodium chromate (Na2CrO4). Na2CrO4 reacts with lead acetate in presence of dil. acetic acid to form yellow precipitate of lead chromate (PbCrO4).

Confirmation of Bromide, Br-

Experiment	Observation	Inference
Silver nitrate test:Acidify a portion of aqueous with dil. HNO3. Boil, cool and add AgNO3 solution.	A light yellow precipitate is formed which is partially soluble in NH4OH.	The pale yellow precipitate is silver bromide which is sparingly soluble in ammonium hydroxide.
Maganese dioxide test: Heat a small quantity of the salt with solid MnO4 and conc. H2SO4.	Evolution of yellow brown vapour of bromine which turn starch paper yellow.	The brown vapours is due to the formation of bromine gas.
Chlorine water test:Acidify a portion of aqueous solution with dil. HCl and add 1-2 ml of carbon disulphide and then chlorine water. Shake vigorously and allow it to stand.	Carbon disulphide layer acquires orange colouration.	Bromine liberated during the reaction being soluble in carbon disulphide (CS2) imparts an orange colour to the CS2 layer.

Note: Chlorine water is prepared by adding drop wise conc. HCl to a small volume of KMnO4 solution till the pink colour is just discharged, the resulting solution is chlorine water.

Confirmation of Iodide, I- 

Experiment	Observation	Inference
Silver nitrate test:Acidify a portion of aqueous solution with dil. HNO3. Boil, cool and add AgNO3 solution.	A yellow precipitate is formed which is insoluble in NH4OH.	The yellow precipitate is silver iodide which is insoluble in ammonium hydroxide.
Maganese dioxide test:Heat a small quantity of the salt with solid MnO2 and conc. H2SO4.	Evolution of violet vapours of iodine which turn starch paper blue.	The violet vapours are due to the formation of iodine gas.
Chlorine water test:Acidify a part of aqueous solution with dil. HCl, and add 1-2 ml of carbon disulphide and then chlorine water. Shake vigorously and allow it to stand.	Carbon disulphide layer acquires violet colouration.	Iodine liberated during the reaction being soluble in carbon disulphide (CS2) imparts an orange colour to the CS2 layer.

Confirmation of Acetate, CH3COO-

Experiment	Observation	Inference
Oxalic acid test:	Take a small quantity of the salt in a watch glass. Mix it with solid oxalic acid. Prepare a paste of it with a few drops of water. Rub the paste and smell it.	Smells like that of vinegar.	Presence of acetate ion.
Ester test:	Take a small quantity of the salt in a test-tube. Add conc. H2SO4 (2 ml) and heat. Now ethyl alcohol (1 ml). Shake. Pour the contents of the tube in a beaker full of water. Stir.	Pleasant fruity smell of ester.	The fruity smell is due to the formation of ethyl acetate.
Ferric chloride test:	Take the salt solution. Add neutral ferric chloride solution. Filter. Divide the filtrate into two portions. (i) To one part, add water and boil. (ii) To second part, add dil. HCl.	Reddish coloured filtrate. Reddish brown precipitate. Reddish colour disappears.	The reddish coloured filtrate is due to the formation of (CH3COO)3Fe. The reddish brown precipitate is due to the formation of (CH3COO) (OH2) Fe. This confirms the presence of acetate ion.

Confirmation of Oxalate, C2O42-

Experiment	Observation	Inference
Calcium chloride test: Take a water extract. Add small amount dil. acetic acid and boil off CO2. Add calcium chloride solution. Add dil HNO3 to the white precipitate and warm.	White precipitate is formed. The precipitate dissolves.	The white precipitate is calcium oxalate (CaC2O4) and is dissolved in dil.HNO3.
Potassium permanganate test:Take a pinch of the salt in test tube and add. dil. Sulphuric acid. Warm to 60-70 °C and add 2-3 drops of KMnO4 solution.	Pink colour of KMnO4 solution is decolourised with the evolution of CO2 gas.	The pink colour of potassium permanganate is decolourised with the evolution of carbon dioxide gas.

Confirmation of Sulphate, SO42-

Experiment	Observation	Inference
Barium chloride test:To a part of aqueous solution of the salt add barium chloride solution. Add dil. HCl to the white precipitate and shake.	A white precipitate is formed. The white precipitate is insoluble in dil. HCl.	The white precipitate is barium sulphate (BaSO4) which is insoluble in dil. HCl
Match stick test:Mix a small amount of the salt with sodium carbonate and a little powdered charcoal so as to get a paste. Take some of this paste on one end of a wooden splinter and heat in the reducing flame till the mass fuses. Dip the fused mass into sodium nitroprusside solution taken in a china dish.	Violet streaks are produced	This confirms the presence of sulphate.
Lead acetate test:To a part of aqueous solution of the salt add lead acetate solution. Add excess of hot ammonium acetate to this precipitate.	A white precipitate is formed which is insoluble in excess of hot ammonium acetate solution.	The white precipitate is lead sulphate (PbSO4) which is insoluble in excess of hot ammonium acetate.

Confirmation of Phosphate, PO43-

Experiment	Observation	Inference
Ammonium molybdate test:To the aqueous solution add concentrated nitric acid and boil. Add ammonium molybdate solution in excess and again boil.	A yellow precipitate is formed.	The deep yellow precipitate is ammonium phosphate molybdate {(NH4)3PO4.12MoO3.6H2O}.
Magnesia mixture test:Take a portion of aqueous solution. Add magnesia mixture and allow to stand.	A white precipitate is obtained.	The white precipitate is magnesium ammonium phosphate (Mg(NH4)PO4).

Simulator Procedure (as performed through the Online Labs)

You can select the preliminary tests from ‘Select the preliminary test’ drop down list.

Physical Examination

• Drag the original salt to the watch glass to put it into the watch glass.
• Drag the dropper to the watch glass to add water to the sample.
• Drag the hand to the watch glass to rub the pre-wetted salt with the fingers.
• If vinegar like smell is produced, acetate is present.
• If rotten eggs smell is produced, sulphide is present.
• Click on the inference icon to see the inference.
• If no smell is produced from the salt, you can go to the next test.

Dry Heating Test

Colourless and Odourless Gas

• Drag the cork to the test tube to close the test tube.
• Click on the knob of the burner to turn it on.
• Drag the delivery tube to the test tube to insert one end into the test tube through the cork.
• Drag test tube containing lime water to the delivery tube to insert the other end of the delivery tube in the lime water.
• If the lime water turns milky, either carbonate or oxalate is present.
• Click on the inference icon to see the inference.
• If no characteristic change is seen, you can go to the next test.
• To redo the test, click on the ‘Reset button’.

Colourless Gas with Odour

• Click on the knob of the burner to turn it on.
• Drag the lead acetate paper to the test tube to hold it over the mouth of the test tube.
• If the lead acetate paper turns black, sulphide is present.
• Click on the inference icon to see the inference.
• If sulphide is absent, drag the glass rod to the bottle to dip it in ammonia solution and again drag it to the test tube to hold it over the mouth of the test tube.
• If white fumes are produced, chloride is present.
• Click on the inference icon to see the inference.
• If no characteristic change is seen, you can go to the next test.
• To redo the test, click on the ‘Reset button’.

Coloured Gases

Click on the knob of the burner to turn it on.

• If greenish yellow gas is evolved, drag the strach - Iodide paper to the test tube to hold it over the mouth of the test tube.
• Click on the inference icon to see the inference.
• If reddish brown vapours are evolved, drag the strach paper to the test tube to hold it over the mouth of the test tube.
• Click on the inference icon to see the inference.
• If dark violet vapours are evolved, drag the strach paper to the test tube to hold it over the mouth of the test tube.
• Click on the inference icon to see the inference.
• If reddish brown gas is evolved, drag the cork to the test tube to close the test tube.
• Drag the delivery tube to the test tube to insert one end into the test tube through the cork.
• Drag test tube containing ferrous sulphate solution  to the delivery tube to insert the other end of the delivery tube in the ferrous sulphate solution.
• Click on the inference icon to see the inference.
• If no characteristic change is seen, you can go to the next test.
• To redo the test, click on the ‘Reset button’.

Dilute Sulphuric Acid Test

• Drag the dropper to the test tube to drop dil. H2SO4 into the salt.
• If colourless gas with the smell of rotten egg is evolved, drag the lead acetate paper to the test tube to hold it in the gas evolved from the mouth of the test tube.
• Click on the inference icon to see the inference.
• If colourless gas with the smell of burning sulphur is evolved, drag the acidified potassium dichromate paper to the test tube to hold it in the gas evolved from the mouth of the test tube.
• Click on the inference icon to see the inference.
• If reddish brown fumes are evolved, drag the cork to the test tube to close the test tube. Then drag the delivery tube to the test tube to insert one end into the test tube through the cork. Finally drag the test tube containing ferrous sulphate solution to the delivery tube to insert the other end of the delivery tube in the ferrous sulphate solution.
• Click on the inference icon to see the inference.
• If colourless odourless gas with brisk effervescence is seen, drag the cork to the test tube to close the test tube. Then drag the delivery tube to the test tube to insert one end into the test tube through the cork. Finally, drag the test tube containing lime water to the delivery tube to insert the other end of the delivery tube in the lime water.
• Click on the inference icon to see the inference.
• If no characteristic change is seen, you can go to the next test.
• To redo the test, click on the ‘Reset button’.

Potassium Permanganate Test

• Drag the original salt to the test tube to put it into the test tube.
• Drag the dropper to the test tube to drop dil. H2SO4 into it.
• Click on the knob of the burner to turn it on.
• Again drag the dropper to the test tube to drop dil. H2SO4 into it.
• Drag the dropper to the test tube to drop potassium permanganate solution into it.
• If the colour of potassium permanganate is decolourised, either chlorine or bromide or iodide is present.
• Click on the inference icon to see the inference.
• If potassium permanganate is not decolourised, click on the knob of the burner to turn it on and heat the solution.
• If the colour of potassium permanganate is decolourised, oxalate is present.
• Click on the inference icon to see the inference.
• If no characteristic change is seen, you can go to the next test.
• To redo the test, click on the ‘Reset button’.

Concentrated Sulphuric Acid Test

• Drag the original salt to put it into the test tube.
• Drag the dropper to the test tube to drop conc. H2SO4 into it.
• If colourless gas with pungent smell is evolved, drag the glass rod to the bottle containing aqueous ammonia to dip it in ammonia solution and again drag it to the test tube to hold it in the colourless gas.
• Click on the inference icon to see the inference.
• If white fumes are produced, chloride is present.
• If reddish brown gas with pungent smell is evolved, drag the starch paper to the test tube to hold it in the reddish–brown gas.
• If the starch paper turns yellow, bromide is present.
• Click on the inference icon to see the inference.
• If deep violet vapours with pungent smell is evolevd, drag the starch paper to the tests tube to hold it in the violet vapours.
• If the starch paper turns blue, iodide is present.
• Click on the inference icon to see the inference.
• If colourless gas is evolved, drag the cork to the test tube to close the test tube. Then drag the delivery tube to the test tube to insert it in between the test tube and lime water.
• If lime water turns milky, oxalate is present.
• Click on the inference icon to see the inference.
• If no characteristic change is seen, you can go to the next test.
• To redo the test, click on the ‘Reset button’.

Independent Group Test

• Drag the dropper to the test tube to drop dil.HCl into the salt.
• Click on the knob of the burner to turn it on.
• Drag the funnel to the test tube placed in the stand to place it over the test tube.
• Drag the test tube to the funnel to filter the solution in the test tube.
• Drag the dropper to drop barium chloride solution into the solution in the test tube.
• If white precipitate is formed, sulphate is present.
• Click on the inference icon to see the inference.
• If sulphate is absent, drag the dropper to the test tube to drop conc. HNO3 into the salt.
• Click on the knob of the burner to turn it on.
• Drag the dropper to drop ammonium molybdate solution into it.
• Click on the inference icon to see the inference.
• To redo the test, click on the ‘Reset button’.

You can select the confirmatory tests from ‘Select the confirmation test’ drop down list.

Confirmation of Carbonate

Dilute HCl Test

• Drag the dropper to the test tube to drop dil.HCl into it.
• Drag the cork to the test tube to close the test tube.
• Drag the delivery tube to the test tube to insert it into the test tube through the cork.
• Drag test tube containing lime water towards the delivery tube to insert the other end of the delivery tube in the lime water.
• Click on the inference icon to see the inference.
• To redo the test, click on the ‘Reset button’.

Magnesium sulphate Test

• Drag the dropper to the test tube to drop magnesium sulphate solution into it.
• Click on the inference icon to see the inference.
• To redo the test, click on the ‘Reset button’.

Confirmation of Sulphite

Barium chloride Test

• Drag the dropper to the test tube to drop barium chloride solution into it.
• Drag the dropper to the test tube to drop dil.HCl into it.
• Click on the inference icon to see the inference.
• To redo the test, click on the ‘Reset button’.

Potassium Permanganate Test

• Drag the dropper to the test tube to drop acidified potassium permanganate solution into it.
• Click on the inference icon to see the inference.
• To redo the test, click on the ‘Reset button’.

Potassium Dichromate Test

• Drag the dropper to the test tube to drop acidified potassium dichromate solution into it.
• Click on the inference icon to see the inference.
• To redo the test, click on the ‘Reset button’.

Confirmation of Sulphide

Sodium Nitroprusside Test

• Drag the dropper to the test tube to drop sodium nitroprusside solution into it.
• Click on the inference icon to see the inference.
• To redo the test, click on the ‘Reset button’.

Lead Acetate Test

• Drag the dropper to the test tube to drop lead acetate solution into it.
• Click on the inference icon to see the inference.
• To redo the test, click on the ‘Reset button’.

Cadmium Carbonate Test

• Drag the dropper to the test tube to drop cadmium carbonate suspension into it.
• Click on the inference icon to see the inference.
• To redo the test, click on the ‘Reset button’.

Confirmation of Nitrite

Ferrous Sulphate Test

• Drag the dropper to the test tube to drop ferrous sulphate solution into it.
• Drag the dropper to the test tube to drop dilute acetic acid into it.
• Click on the inference icon to see the inference.
• To redo the test, click on the ‘Reset button’.

Starch Iodide Test

• Drag the dropper to the test tube to drop dil.H2SO4 into it.
• Drag the dropper to the test tube to drop potassium iodide solution into it.
• Drag the dropper to the test tube to drop starch solution into it.
• Click on the inference icon to see the inference.
• To redo the test, click on the ‘Reset button’.

Diphenylamine Test

• Drag the dropper to the test tube to drop diphenylamine into it.
• Click on the inference icon to see the inference.
• To redo the test, click on the ‘Reset button’.

Confirmation of Nitrate

Diphenylamine Test

• Drag the dropper to the test tube to drop diphenylamine into it.
• Click on the inference icon to see the inference.
• To redo the test, click on the ‘Reset button’.

Copper Chips Test

• Click on the knob of the burner to turn it on.
• Drag the dropper to the test tube to drop conc.H2SO4 into the salt in the test tube.
• Drag the forceps towards the test tube to put the copper chips into it.
• Click on the inference icon to see the inference.
• To redo the test, click on the ‘Reset button’.

Brown Ring Test

• Drag the dropper to the test tube to drop ferrous sulphate solution into the test tube containing salt solution.
• Drag the dropper to the test tube to drop conc.H2SO4 slowly along the sides of the test tube.
• Click on the inference icon to see the inference.
• To redo the test, click on the ‘Reset button’.

Confirmation of Chloride

Silver Nitrate Test

• Drag the dropper to the test tube to drop salt solution into it.
• Drag the dropper to the test tube to drop dil. HNO3 into it.
• Click on the knob of the burner to turn it on.
• Drag the dropper to the test tube to drop silver nitrate solution into it.
• Click on the inference icon to see the inference.
• To redo the test, click on the ‘Reset button’.

Manganese Dioxide Test

• Drag the original salt to the test tube to put it into the test tube.
• Drag manganese dioxide to the test tube to put it into the test tube.
• Drag the dropper to the test tube to drop conc. H2SO4 into it.
• Click on the knob of the burner to turn it on.
• Drag the starch-iodide paper to the test tube to hold it in the gas evolved from the test tube.    
• Click on the inference icon to see the inference
• To redo the test, click on the ‘Reset button’.

Chromyl Chloride Test

• Drag the original salt to the test tube to put it into the test tube.
• Drag the potassium dichromate powder to the test tube to put it into the test tube.
• Drag the dropper to the test tube to drop conc. H2SO4 into it.
• Drag the cork to the test tube to close the test tube.
• Drag the delivery tube to the test tube to insert it into the test tube through the cork.
• Click on the knob of the burner to turn it on.
• Drag the dropper to the test tube to drop dil. acetic acid (CH3COOH) into it.
• Drag the dropper to the test tube to drop lead acetate solution into it.
• Click on the inference icon to see the inference
• To redo the test, click on the ‘Reset button’.

Confirmation of Bromide

Silver Nitrate Test

• Drag the dropper to the test tube to drop salt solution into it.
• Drag the dropper to the test tube to drop dil. HNO3 into it.
• Click on the knob of the burner to turn it on.
• Drag the dropper to the test tube to drop silver nitrate solution into it.
• Click on the inference icon to see the inference
• To redo the test, click on the ‘Reset button’.

Manganese Dioxide Test

• Drag the original salt to the test tube to put it into the test tube.
• Drag manganese dioxide to the test tube to put it into the test tube.
• Drag the dropper to the test tube to drop conc. H2SO4 into it.
• Click on the knob of the burner to turn it on.
• Drag the starch paper to the test tube to hold it in the gas evolved from the test tube.    
• Click on the inference icon to see the inference
• To redo the test, click on the ‘Reset button’.

Chlorine Water Test

• Drag the dropper to the test tube to drop salt solution into it.
• Drag the dropper to the test tube to drop dil.HCl into it.
• Drag the dropper to the test tube to drop carbon disulphide into it.
• Drag the dropper to the test tube to drop chlorine water into it.
• Drag the test tube to shake it.
• Click on the inference icon to see the inference
• To redo the test, click on the ‘Reset button’.            

Confirmation of Iodide

Silver Nitrate Test

• Drag the dropper to the test tube to drop salt solution into it.
• Drag the dropper to the test tube to drop dil. HNO3 into it.
• Click on the knob of the burner to turn it on.
• Drag the dropper to the test tube to drop silver nitrate solution into it.
• Click on the inference icon to see the inference
• To redo the test, click on the ‘Reset button’.

Manganese Dioxide Test

• Drag the original salt to the test tube to put it into the test tube.
• Drag manganese dioxide to the test tube to put it into the test tube.
• Drag the dropper to the test tube to drop conc. H2SO4 into it.
• Click on the knob of the burner to turn it on.
• Drag the starch paper to the test tube to hold it in the gas evolved from the test tube.    
• Click on the inference icon to see the inference
• To redo the test, click on the ‘Reset button’.

Chlorine Water Test

• Drag the dropper to the test tube to drop salt solution into it.
• Drag the dropper to the test tube to drop dil.HCl into it.
• Drag the dropper to the test tube to drop carbon disulphide into it.
• Drag the dropper to the test tube to drop chlorine water into it.
• Drag the test tube to shake it.
• Click on the inference icon to see the inference
• To redo the test, click on the ‘Reset button’.    

Confirmation of Acetate

Oxalic Acid Test

• Drag the watch glass to place it in the table.
• Drag the original salt to the watch glass to put it into the watch glass.
• Drag the oxalic acid crystals to the watch glass to put it into watch glass.
• Drag the bottle of distilled water to the table and drag the dropper to the watch glass to drop distilled water into the mixture.
• Drag the hand to the watch glass to rub the pre-wetted mixture with the fingers.    
• Click on the inference icon to see the inference
• To redo the test, click on the ‘Reset button’.    

Ester Test

• Drag the original salt to the test tube to put it into the test tube.
• Drag the bottle of conc.H2SO4 to the table and drag the dropper to the test tube to drop conc. H2SO4 into the salt.
• Click on the knob of the burner to turn it on.
• Drag the bottle of ethyl alcohol to the table and drag the dropper to the test tube to drop ethyl alcohol into it.
• Drag the beaker containing water near the burner to place it on the table.
• Click on the test tube and drag it to shake it well and pour the contents into beaker containing water.
• Click on the inference icon to see the inference
• To redo the test, click on the ‘Reset button’.    

Ferric Chloride Test

• Drag the dropper to the first test tube placed in the test tube rack to drop the salt solution into it.
• Drag the dropper to the test tube to drop ferric chloride solution into it.
• Drag the filter funnel to the second test tube in the test tube rack to place it over the test tube.
• Drag the test tube to the funnel to filter the contents into the second test tube through the funnel.
• Drag the test tube to the stand to pour half of the reddish coloured filtrate into the test tube fixed to the stand.
• Drag the dropper to the stand to drop water into the test tube containing reddish coloured filtrate.
• Click on the knob of the burner to turn it on.
• Click on the inference icon to see the inference.
• Drag the dropper to the test tube in the test tube rack to drop dil. HCl into the reddish coloured filtrate.        
• Click on the inference icon to see the inference.
• To redo the test, click on the ‘Reset button’.    

Confirmation of Oxalate

Calcium Chloride Test            

• Drag the dropper to the test tube to drop salt solution into it.
• Drag the dropper to the test tube to drop acetic acid (C2H4O2) into it.
• Click on the knob of the burner to turn it on.
• Drag the dropper to the test tube to drop calcium chloride solution into it.
• Drag the dropper to the test tube to drop dil.HNO3 into it.
• Click on the knob of the burner to turn it on.
• Click on the inference icon to see the inference.
• To redo the test, click on the ‘Reset button’.    

Potassium Permanganate Test    

• Drag the original salt to the test-tube to put it into test tube.
• Drag the dropper to the test tube to drop dil. H2SO4 into it.
• Click on the knob of the burner to turn it on.
• Drag the dropper to the test tube to drop potassium permanganate solution into it.
• Click on the inference icon to see the inference.
• To redo the test, click on the ‘Reset button’.    

Confirmation of Sulphate

Barium Chloride Test

• Drag the dropper to the test tube to drop barium chloride solution into it.
• Drag the dropper to the test tube to drop dil.HCl into it.
• Click on the inference icon to see the inference
• To redo the test, click on the ‘Reset button’.

Match Stick Test

• Drag the spatula to the watch glass to add sodium carbonate to the original salt.
• Drag the spatula to the watch glass to put powdered charcoal into it.
• Drag the bottle of distilled water to the watch glass to drop water into the mixture.
• Drag the glass rod to the watch glass to mix the contents.
• Drag the dish containing sodium nitroprusside solution to the watch glass to place it on the table.
• Click on the knob of the burner to turn it on and click on the air adjusting disc to close the air hole to get the reducing flame.
• Drag the match stick to the watch glass to dip it into the mixture.
• Drag the match stick to the burner to heat the mixture on the tip of the match stick in the reducing flame.
• Drag the match stick towards the dish to dip the fused mass into the sodium nitroprusside solution.
• Click on the inference icon to see the inference
• To redo the test, click on the ‘Reset button’.

Lead Acetate Test

• Drag the dropper to the test tube to drop lead acetate solution into it.
• Drag the dropper to the test tube to drop hot ammonium acetate solution into it.    
• Click on the inference icon to see the inference.
• To redo the test, click on the ‘Reset button’.

Confirmation of Phosphate

Ammonium Molybdate Test

• Drag the dropper to the test tube to drop conc. HNO3 into it.
• Click on the knob of the burner to turn it on and boil the contents.
• Drag the dropper to the test tube to drop excess of ammonium molybdate solution into it.
• Click on the knob of the burner to turn it on and again boil the contents.
• Click on the inference icon to see the inference.
• To redo the test, click on the ‘Reset button’.

Magnesia Mixture Test

• Drag the dropper to the test tube to drop salt solution into it.
• Drag the dropper to the test tube to drop magnesia mixture into it.
• Click on the inference icon to see the inference.
• To redo the test, click on the ‘Reset button’.

Precautions

• Handle the chemicals and apparatus with care.
• When heating a solution in a test tube, students should hold the test tube with a proper holder.
• While heating, the mouth of the test tube should not point towards the student or any other person in the lab.
• Students should wear lab coats and goggles while performing the experiment.