Class 12 Chemistry practical list: virtual lab with viva questions
117 experiments for Class 12 Chemistry, each one a 3D virtual lab you can open in your browser. 2 are free. Pick an experiment below to read its aim and theory, then run it yourself.
A virtual lab lets you repeat a practical as often as you like before you do it on the bench: you see the apparatus, change one value at a time and watch how the reading changes. It is useful to prepare for the practical exam, to revise the theory behind each experiment and to understand where errors come from. PractiSci follows the NCERT chapters, so the experiments are grouped unit by unit below.
Unit 0: All units
- Open bench (free mixing)Mix anything on the shelf. The engine works out what reacts, how fast and how much.
Unit 1: Solutions
- Elevation of boiling pointCompare the boiling point of pure water with that of a glucose solution and calculate Kb.
- Depression of freezing pointCool water and a urea solution in a freezing mixture and measure how much the solute lowers the freezing point.
- Osmosis through a semipermeable membraneWatch water move through a membrane into a sucrose solution and estimate the osmotic pressure π = CRT.
- Van 't Hoff factor from freezing pointsCompare the freezing points of 0.5 m glucose, NaCl and CaCl₂ solutions and find the van 't Hoff factor i.
Unit 2: Electrochemistry
- Conductivity of strong and weak electrolytesMeasure the conductivity of 0.1 M HCl, 0.1 M acetic acid and distilled water.
- Electrolytic refining of copperUse copper electrodes in acidified CuSO₄ and show that copper is transferred from the anode to the cathode.
- Daniell cell and the Nernst equationBuild a Zn | Zn²⁺ ‖ Cu²⁺ | Cu cell, read its emf and watch it change as the cell discharges.
- Electrolysis of brine (chlor-alkali)Electrolyse concentrated NaCl solution and identify H₂, Cl₂ and NaOH.
- Electrolysis of copper sulphate (inert electrodes)Electrolyse CuSO₄ solution with graphite electrodes and identify the products at each electrode.
- Electrolysis of potassium iodideSee iodine forming at the anode and alkali at the cathode when KI solution is electrolysed.
- Electrolysis of waterShow that pure water hardly conducts, then electrolyse acidified water and compare the volumes of H₂ and O₂.
- Copper plating an iron keyElectroplate an iron key with copper.
- Molar conductivity and dilution (Kohlrausch)Measure κ for KCl and acetic acid at two concentrations and calculate Λm = κ × 1000 / c.
Unit 3: Chemical Kinetics
- Catalysis: MnO₂ and hydrogen peroxideShow that MnO₂ speeds up the decomposition of H₂O₂ and is not used up.
- Catalysed decomposition of H₂O₂ (free)Compare H₂O₂ decomposing on its own and with iodide as a catalyst.
- Iodine clock reaction: temperature and rateTime the appearance of the blue colour at room temperature and in a warm bath, and estimate the activation energy.
- Effect of concentration on rate (Mg + HCl)Compare how fast equal pieces of magnesium dissolve in 2 M and 1 M hydrochloric acid.
- Effect of surface area on rate (marble chips vs powder)Compare the rate of CO₂ evolution from marble chips and powdered marble in the same acid.
- Rate of thiosulphate with acidTime how long the cross takes to disappear at different concentrations and temperatures.
Unit 4: The d- and f-Block Elements
- Chromate ⇌ dichromate with pHSwitch between yellow chromate and orange dichromate by changing pH.
- Dichromate test for alcohol (breath analyser)Oxidise ethanol with acidified potassium dichromate and see orange Cr(VI) turn green Cr(III).
- Permanganate in acidic, neutral and alkaline mediaReduce KMnO₄ with sulphite in three media and identify the manganese product from its colour.
- Coloured hydroxides of transition metalsPrecipitate the hydroxides of Cu²⁺, Fe²⁺, Fe³⁺, Ni²⁺ and Co²⁺ and compare their colours.
- Oxidation states of vanadiumReduce vanadium(V) with zinc in acid and watch it pass through four oxidation states, each with its own colour.
Unit 5: Coordination Compounds
- Nickel: hydroxide to hexaammine complexAdd ammonia to Ni²⁺: first a green precipitate, then a violet-blue complex in excess.
- Nickel dimethylglyoxime complexDetect Ni²⁺ with dimethylglyoxime, which forms a rosy-red chelate.
- Prussian blue and Turnbull's blueDistinguish Fe³⁺ and Fe²⁺ using hexacyanoferrate complexes.
- Silver precipitation–complexation ladderMove silver back and forth between precipitates and complexes: AgCl → [Ag(NH₃)₂]⁺ → AgBr → [Ag(S₂O₃)₂]³⁻ → AgI.
- Tetraamminecopper(II) complexAdd ammonia drop by drop to Cu²⁺ and watch a precipitate form and then dissolve as a complex forms.
- Ligand exchange: thiocyanate vs fluorideForm blood-red [Fe(SCN)]²⁺ and decolourise it with fluoride, which forms a more stable complex.
Unit 6: Haloalkanes and Haloarenes
- Reactivity of 1°, 2°, 3° and aryl halides (SN1)Compare how fast different bromides give AgBr with ethanolic silver nitrate.
- Silver nitrate test for halidesIdentify Cl⁻, Br⁻ and I⁻ by the colour of their silver salts and their solubility in ammonia.
Unit 7: Alcohols, Phenols and Ethers
- Lucas test for alcoholsTell primary, secondary and tertiary alcohols apart with Lucas reagent.
- Phenol with bromine waterShow that phenol decolourises bromine water instantly, giving a white precipitate, while ethanol does not.
- Ferric chloride test for phenolDetect phenol with neutral FeCl₃ and compare with an alcohol.
- Sodium with ethanolShow that alcohols react with sodium to give hydrogen, much more gently than water.
Unit 8: Aldehydes, Ketones and Carboxylic Acids
- Sodium hydrogencarbonate test for carboxylic acidsShow that carboxylic acids (but not phenol or alcohols) liberate CO₂ from NaHCO₃.
- 2,4-DNP test for carbonyl compoundsIdentify a carbonyl group (aldehyde or ketone) with Brady's reagent.
- Esterification: ethyl acetateWarm ethanol and acetic acid with a little conc. H₂SO₄ and detect the fruity ester.
- Fehling's testUse Fehling’s solution to detect a reducing sugar / aliphatic aldehyde.
- Iodoform testDetect the CH₃CO– group (and CH₃CH(OH)– group) with iodine and alkali.
- Schiff's test: aldehyde vs ketoneDistinguish an aldehyde from a ketone using Schiff's reagent.
- Tollens' silver mirrorDistinguish an aldehyde from a ketone with Tollens’ reagent.
Unit 9: Amines
- Aniline with bromine waterSee how strongly –NH₂ activates the benzene ring.
- Diazotisation and azo dye testDiazotise aniline at 0–5 °C and couple it with β-naphthol to make an orange-red dye; see what happens when it is warm.
- Carbylamine (isocyanide) testIdentify a primary amine by the foul smell of the isocyanide formed with chloroform and alcoholic KOH.
- Hinsberg's test for 1°, 2° and 3° aminesDistinguish primary, secondary and tertiary amines with benzenesulphonyl chloride.
Unit 10: Biomolecules
- Benedict's test for reducing sugarsHeat glucose, fructose and sucrose with Benedict's solution and find which are reducing sugars.
- Biuret test for proteinsDetect peptide bonds in egg albumin with alkaline copper sulphate.
- Molisch's test for carbohydratesDetect carbohydrates (glucose, sucrose, starch) with α-naphthol and conc. H₂SO₄.
- Ninhydrin test for amino acidsHeat glycine with ninhydrin and see Ruhemann's purple.
- Saponification: making soapHydrolyse a fat with sodium hydroxide to make soap and glycerol.
- Seliwanoff's test: ketose vs aldoseDistinguish fructose (a ketose) from glucose (an aldose).
- Acid hydrolysis of starchHydrolyse starch with acid, follow it with iodine, and show that glucose is formed.
- Starch–iodine testDetect starch with iodine and see the colour disappear on heating.
- Xanthoproteic testWarm egg albumin with conc. nitric acid and observe the yellow colour.
Unit 11: Salt Analysis (Lab Manual)
- Test for acetate ionIdentify acetate by the vinegar smell with dilute H₂SO₄ and the red colour with neutral FeCl₃.
- Test for carbonate ion (free)Identify carbonate by effervescence with dilute acid and the lime water test.
- Brown ring test: nitrate and nitriteConfirm nitrate with the brown ring test and distinguish it from nitrite.
- Test for phosphate ionIdentify phosphate with ammonium molybdate (canary-yellow precipitate) and magnesia mixture.
- Test for sulphate ionIdentify sulphate with barium chloride; the precipitate does not dissolve in conc. HCl. Confirm with lead acetate.
- Test for sulphide ionIdentify sulphide by H₂S gas (lead acetate paper) and the sodium nitroprusside test.
- Tests for aluminium and zinc ionsIdentify Al³⁺ (white gelatinous hydroxide, soluble in excess NaOH) and Zn²⁺ (white ZnS, white ferrocyanide).
- Test for ammonium ion (zero group)Identify NH₄⁺ by ammonia evolved with NaOH and by Nessler's reagent.
- Test for copper ion (group II)Identify Cu²⁺: black CuS with H₂S (Na₂S), deep blue with excess ammonia, chocolate-brown with K₄[Fe(CN)₆].
- Calcium, strontium and barium (group V)Precipitate group V carbonates with ammonium carbonate and identify each ion by a specific test and its flame colour.
- Test for iron(III) ion (group III)Identify Fe³⁺: reddish-brown precipitate with NH₄OH/NH₄Cl, Prussian blue with ferrocyanide, blood red with thiocyanate.
- Test for lead ion (group I)Precipitate PbCl₂ with dilute HCl, dissolve it in hot water and confirm Pb²⁺ with KI and K₂CrO₄.
- Test for magnesium ion (group VI)Identify Mg²⁺ with disodium hydrogenphosphate in ammoniacal solution.
- Tests for nickel and cobalt ions (group IV)Both give black sulphides; distinguish Ni²⁺ (red with DMG) from Co²⁺ (blue with conc. HCl).
Unit 12: Surface Chemistry (Lab Manual)
- Ferric hydroxide sol: preparation and coagulationPrepare a red-brown Fe(OH)₃ sol by hydrolysis of FeCl₃ in boiling water, then coagulate it with an electrolyte.
Unit 13: NEET / JEE Practice Labs (Class XII)
- Identify a primary, a secondary and a tertiary amineTube 1 holds aniline, tube 2 diethylamine and tube 3 triethylamine (in a random order). Use the carbylamine and Hinsberg tests to classify them.
- Amphoteric hydroxides of Al³⁺, Cr³⁺ and Zn²⁺Add NaOH to Al³⁺, Cr³⁺ and Zn²⁺ solutions and show that all three hydroxides precipitate first and dissolve in excess alkali.
- Identify phenol, aniline and ethanolTubes 1, 2 and 3 hold phenol, aniline and ethanol (random order). Use neutral FeCl₃, bromine water and sodium to tell them apart.
- Autocatalysis: Mn²⁺ speeds up KMnO₄ + oxalic acidCompare the decolourisation of KMnO₄ by acidified oxalic acid at room temperature with and without a little added Mn²⁺.
- Identify glycine, a protein, glucose and sucroseThe four tubes hold glycine, a protein, glucose and sucrose in a random order. Use ninhydrin, the biuret test and Benedict’s solution to identify them.
- Boiling-point elevation: NaCl vs glucose and the van 't Hoff factorBoil 50 g of water containing 0.05 mol of NaCl, 0.05 mol of glucose and nothing, and find i for NaCl from the elevation.
- Calcium oxalate: the confirmatory test for Ca²⁺Precipitate Ca²⁺ with ammonium oxalate and show that the precipitate does not dissolve in acetic acid.
- Identify glucose, fructose, sucrose and starchThe four tubes hold glucose, fructose, sucrose and starch in a random order. Use iodine, Benedict’s and Seliwanoff’s reagents to identify them.
- Galvanic cell: Cu | Cu²⁺ ‖ Ag⁺ | AgBuild the cell Cu | Cu²⁺ ‖ Ag⁺ | Ag, read its emf and compare it with E°cell calculated from the electrode-potential table.
- Galvanic cell: Fe | Fe²⁺ ‖ Ag⁺ | AgBuild the cell Fe | Fe²⁺ ‖ Ag⁺ | Ag, read its emf and compare it with E°cell calculated from the electrode-potential table.
- Galvanic cell: Fe | Fe²⁺ ‖ Cu²⁺ | CuBuild the cell Fe | Fe²⁺ ‖ Cu²⁺ | Cu, read its emf and compare it with E°cell calculated from the electrode-potential table.
- Galvanic cell: Mg | Mg²⁺ ‖ Ag⁺ | Ag (the strongest couple)Build the cell Mg | Mg²⁺ ‖ Ag⁺ | Ag, read its emf and compare it with E°cell calculated from the electrode-potential table.
- Galvanic cell: Mg | Mg²⁺ ‖ Fe²⁺ | FeBuild the cell Mg | Mg²⁺ ‖ Fe²⁺ | Fe, read its emf and compare it with E°cell calculated from the electrode-potential table.
- Galvanic cell: Mg | Mg²⁺ ‖ Zn²⁺ | ZnBuild the cell Mg | Mg²⁺ ‖ Zn²⁺ | Zn, read its emf and compare it with E°cell calculated from the electrode-potential table.
- Galvanic cell: Zn | Zn²⁺ ‖ Fe²⁺ | FeBuild the cell Zn | Zn²⁺ ‖ Fe²⁺ | Fe, read its emf and compare it with E°cell calculated from the electrode-potential table.
- Chromate precipitates of Ba²⁺, Pb²⁺ and Ag⁺Add potassium chromate to three metal ions and tell them apart by the colour of their chromates.
- Concentration cell: Cu | Cu²⁺ (0.2 M) ‖ Cu²⁺ (1 M) | CuMeasure the emf of a copper concentration cell with a five-fold concentration ratio and compare with the Nernst equation.
- Concentration cell: Zn | Zn²⁺ (0.1 M) ‖ Zn²⁺ (1 M) | ZnBuild a zinc concentration cell and show that its emf, about 29.6 mV, comes only from the concentration difference.
- Conductivity and ionic charge: NaCl, CaCl₂ and an Al³⁺ saltMeasure κ of 0.1 M NaCl, CaCl₂ and Al³⁺ solutions and show that more highly charged / more numerous ions conduct better.
- Conductometric titration: HCl with NaOH (V-shaped curve)Add 0.1 M NaOH to 50 mL of 0.1 M HCl in portions, measuring the conductivity each time, and locate the end point at the minimum.
- Conductometric titration: acetic acid with NaOHAdd 0.1 M NaOH to 50 mL of 0.1 M acetic acid in portions and show that the conductivity rises, with a sharper rise after the end point.
- Decomposition voltage of copper sulphateElectrolyse 0.5 M CuSO₄ with graphite electrodes at 1 V and 2 V and show that current flows only above the decomposition voltage (1.29 V).
- Decomposition voltage of potassium iodideElectrolyse 0.1 M KI at 1 V and 2 V; iodine and hydrogen form only above about 1.35 V.
- Decomposition voltage of sodium bromideElectrolyse 0.1 M NaBr at 1 V and 3 V: bromine and hydrogen form only above the decomposition voltage (about 1.9 V).
- Decomposition voltage of water: why 1.23 V is not enoughElectrolyse dilute H₂SO₄ at 2 V and at 3 V: no gas at 2 V even though E° for water decomposition is only 1.23 V.
- Electrolysis of aqueous sodium bromideElectrolyse NaBr solution with inert electrodes and identify H₂ at the cathode and Br₂ at the anode.
- Faraday's first law: mass of copper deposited ∝ chargeElectrolyse CuSO₄ solution and verify that the mass of copper deposited equals Q × M / (nF).
- Electrochemical equivalent of silverElectrolyse AgNO₃ solution, measure the silver deposited for a given charge and compare Z with the theoretical value.
- Potassium ferrocyanide tests for Cu²⁺, Zn²⁺ and Fe³⁺Use K₄[Fe(CN)₆] to identify copper (chocolate brown), zinc (white) and iron(III) (Prussian blue).
- Group I cations: separating Pb²⁺ from Ag⁺ as chloridesPrecipitate Pb²⁺ and Ag⁺ with dilute HCl and tell the two white chlorides apart by hot water and ammonia.
- Iodine clock: order of reaction with respect to H₂O₂Keep [I⁻] the same and use 20 mL, 10 mL and 5 mL of 0.1 M H₂O₂ (made up to 20 mL with water) to find the order in H₂O₂.
- Iodine clock: order of reaction with respect to iodideRun the iodine clock with 0.05 M, 0.1 M and 0.5 M iodide at the same time and show that the time to the blue colour is inversely proportional to [I⁻].
- Effect of temperature on rate: estimating EaRun the thiosulphate–acid reaction at room temperature and at about 50 °C side by side and use the times to estimate the activation energy.
- Concentration cell: Cu | Cu²⁺ (0.1 M) ‖ Cu²⁺ (1 M) | CuBuild a cell with identical copper electrodes in 0.1 M and 1 M CuSO₄ and show that its emf follows E = (0.0592 / n) log (C₂ / C₁).
- Identify four unknown organic liquidsThe tubes hold ethanal, propanone, ethanol and phenol in a random order. Use 2,4-DNP, Fehling’s solution, iodine–NaOH and neutral FeCl₃ to tell them apart.
- Magnesium ammonium phosphate: test for Mg²⁺Detect Mg²⁺ as the white crystalline precipitate of MgNH₄PO₄ in an ammoniacal solution.
- Rate of reaction vs concentration: marble with 0.1, 1 and 2 M HClAdd 1 g of marble chips to three flasks of HCl of different molarity and compare the CO₂ evolved after the same time.
- Coloured metal sulphidesAdd sodium sulphide to six metal-ion solutions and learn which sulphides are black, white or flesh-coloured.
- Molar mass of an unknown solid A from freezing-point depressionDissolve 0.9 g of unknown solid A in 10 g of water, measure the freezing point and calculate its molar mass.
- Molar mass of an unknown solid B from freezing-point depressionRepeat the molar-mass determination with 0.6 g of a different unknown solid B in 10 g of water.
- Identify four unknown metal-ion solutionsFour tubes hold Cu²⁺, Fe³⁺, Pb²⁺ and Zn²⁺ in a random order. Use NaOH, KI, KSCN and NH₃ to tell them apart.
- Order of reaction with respect to hydrochloric acidKeep the thiosulphate the same and vary the amount of HCl (5, 2.5 and 1.25 mL of 2 M, each made up to 5 mL with water) to find the order in H⁺.
- Order of reaction with respect to thiosulphateRun the thiosulphate–acid reaction with 100 %, 50 % and 25 % thiosulphate side by side and show that time ∝ 1 / concentration (first order).
- Solubility of lead chloride changes with temperaturePrecipitate white PbCl₂, dissolve it by heating and see it crystallise again on cooling in ice.
- Inversion of sucrose: a non-reducing sugar becomes reducingShow that sucrose does not reduce Benedict’s solution until it has been hydrolysed by dilute acid into glucose and fructose.
Frequently asked questions
Can I do the Class 12 Chemistry practicals online?
Yes. PractiSci has 117 interactive 3D chemistry experiments for Class 12. You change the values, watch the result in real time and read the numbers off live graphs, on a phone or a laptop, with nothing to install.
Are these the experiments in the NCERT Chemistry practical syllabus?
The labs follow the NCERT Class 12 Chemistry chapters and practicals, and add NEET and JEE level experiments. Your school or board may set its own list, so check it with your teacher and use this page to find the matching experiment.
Do the labs have viva questions?
Each lab has its aim, theory, procedure and observations next to the experiment, so you can revise while you work.
Is it free?
A number of labs in every subject are free forever and need no card (2 of these 117 chemistry labs are free). The NEET-level and advanced labs are part of a PractiSci plan.
Can I use it in Hindi?
Yes. Switch between English and हिन्दी from the header at any time.
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