Lab
Virtual lab
Real apparatus, real technique, and results computed live by chemistry models. Every experiment can be done wrong, redone, and compared against the model.
39 experiments · 9 areas · ≈ 985 min at the bench
How every experiment runs
- Predict first Read the aim and commit to what you expect.
- Run the bench Every reading is computed live by the model; mistakes are allowed.
- Record and compare Set your data beside the model and the literature value.
- Back to the real lab Safety, technique and error sources: what a screen cannot replace.
Showing 39 experiments
- Measurement Identify a metal by its density Weigh an unknown metal painted grey, find its volume by water displacement, and compare the density — with its uncertainty — against handbook values to find out what it is.
- Measurement Iron by spectrophotometry: a calibration curve and an unknown Make a series of iron standards with pipettes and volumetric flasks, develop the colour and read the absorbance at 510 nm, fit the calibration line by least squares, then measure the unknown and reagent blanks and report the iron concentration with its confidence interval and detection limit.
- Measurement Avogadro’s number from Brownian motion Follow suspended grains under the microscope as Perrin did, get the diffusion coefficient and the Avogadro constant from the mean-square displacement, and see how the number of grains decides how far you can trust the result.
- Acids, bases and titration Acid–base titration: find an unknown concentration Deliver standard NaOH drop by drop, catch the drop where the indicator turns, and map the whole titration curve with a pH meter.
- Acids, bases and titration Water hardness by EDTA titration Titrate a tap-water sample with 0.01000 M EDTA at pH 10 with Eriochrome Black T, watch the wine red turn through violet to pure blue, and report the total hardness as CaCO₃. Then use a calcium-only standard to discover why a little magnesium is needed.
- Acids, bases and titration Iron in a tablet by redox titration Dissolve an iron(II) sulfate tablet in dilute sulfuric acid and titrate it with potassium dichromate (diphenylamine sulfonate indicator) or permanganate (its own indicator) to find its iron in milligrams. A platinum electrode shows the solution potential throughout: compare how early and how sharply the violet endpoint appears with and without phosphoric acid.
- Acids, bases and titration Dissolved oxygen by the Winkler method Fix the oxygen in a water sample as a brown precipitate, release iodine with acid and titrate it with thiosulfate. Compare cold, warm and undersaturated samples and see how dissolved oxygen depends on temperature.
- Acids, bases and titration Protein by Kjeldahl nitrogen Digest, distil and titrate: measure the nitrogen in milk, flour, peanuts and gelatin, convert it to protein with 6.25 and with Jones’s special factors, and see how much a “protein content” depends on the factor.
- Acids, bases and titration The solubility product of calcium hydroxide Shake excess calcium hydroxide with water, filter, and titrate the dissolved hydroxide with hydrochloric acid. The product of concentrations comes out about five times the tabulated Ksp; the bench shows step by step how ion pairs and activity coefficients bring it back to 6.5 × 10⁻⁶, and why the common ion in CaCl₂ lowers the solubility less than a constant Ksp predicts.
- Heat and energy The molar volume of hydrogen and the gas constant Weigh a strip of magnesium, let it react with hydrochloric acid inside a gas burette standing mouth-down in water, and collect the hydrogen over water. Level the water, subtract its vapour pressure, and work out the gas constant R and the molar volume of hydrogen at 0 °C and 100 kPa from your reading — then see how much each forgotten correction costs.
- Heat and energy Boyle’s law in a molecular box Move the piston of a genuinely running 2D molecular-dynamics box, measure the pressure, and plot the P–1/V line yourself.
- Heat and energy Atomic masses from specific heats Drop hot metal into a calorimeter, get its specific heat from the temperature rise, and then — as nineteenth-century chemists did — combine the Dulong–Petit law with the mass of an oxide to fix the valence and atomic mass of three unknown metals.
- Heat and energy Calorimetry: measuring reaction enthalpies With two polystyrene cups, a temperature probe and a stirrer, calibrate the calorimeter, then measure the heat of neutralisation and the enthalpies of solution inside cold and hot packs.
- Heat and energy Molar mass by freezing-point depression Record cooling curves of pure water and of a solution in an ice–salt bath, and turn the difference in freezing points into the molar mass of an unknown.
- Heat and energy The smelter: which reducing agent works? Pair ores with coke, carbon monoxide, hydrogen, aluminium powder and magnesium in a virtual smelter, set the furnace temperature, and let Ellingham thermodynamics decide whether metal comes out.
- Spectroscopy and colour Flame tests and discharge tubes: reading atomic fingerprints Put metal salts into a flame and split the colour into lines with a spectroscope; compare the line spectra of hydrogen, helium, neon and mercury tubes; then identify an unknown sample from its lines alone.
- Spectroscopy and colour Spectrophotometry: measure the spectrochemical series Record the absorption spectra of nine nickel(II) and chromium(III) complexes, find the lowest-energy d–d band, convert its wavelength into the splitting Δo and rank the ligands by it.
- Spectroscopy and colour Manganese in steel by spectrophotometry Oxidise the manganese in a steel sample to purple permanganate, compare the spectra of a standard and the steel solution to choose the analytical wavelength, then calibrate with KMnO₄ standards and report the steel’s manganese content. The steel’s chromium quietly spoils the wrong wavelength.
- Spectroscopy and colour Absorption spectra of conjugated dyes: a particle in a box Measure the absorption maxima of nine cyanine dyes in three families, calculate them with a one-dimensional particle in a box, then fit the box length by least squares — and see how well the simplest quantum model describes nine measured peaks.
- Spectroscopy and colour The infrared spectrum of HCl gas: a bond length Record the fundamental band of HCl gas on an FTIR, number every line of the P and R branches, obtain the rotational constants of both vibrational levels from combination differences, and finish with the H–Cl bond length — a classic of the physical chemistry laboratory.
- Structure and crystals Powder diffraction: identify an unknown metal A pinch of metal powder, a beam of copper X-rays and one diffraction pattern. From the peak positions, work out the lattice type and the lattice parameter, then find the metal on a reference card.
- Heat and energy Thermogravimetry of calcium oxalate Heat calcium oxalate monohydrate on a thermobalance, identify the gases from its three mass-loss steps, and use peak temperatures at several heating rates to find the activation energy of each step.
- Heat and energy Cooling curves: the bismuth–cadmium diagram Let bismuth–cadmium melts of several compositions cool slowly, read the liquidus and eutectic temperatures from the breaks and arrests of their curves, and draw the phase diagram yourself.
- Spectroscopy and colour Chloride quenching of quinine fluorescence Excite acidic quinine with a pulsed laser, record the fluorescence decay and fit its lifetime; repeat at several chloride concentrations, obtain the quenching rate constant from a Stern–Volmer plot, and compare it with the diffusion limit.
- Structure and crystals BET surface area of a titania reference material Run a static manometric sorption analyser by the protocol in the NIST SRM 1898 certificate: weigh, outgas, measure the free space with helium, immerse in liquid nitrogen, dose nitrogen between 0.05 and 0.30, and compare the BET surface area with the certified value.
- Spectroscopy and colour Sorting metals with a hand-held XRF analyser Excite X-ray fluorescence from stainless steel, brass, solder, a gold ring and a handful of contaminated soil, assign every peak to an element from NIST line energies — and meet the notorious overlap of lead and arsenic.
- Spectroscopy and colour Blood colour and two-wavelength oximetry Compute the colour of blood at different saturations from the absorption spectra of oxy- and deoxyhaemoglobin, then read the saturation from the ratio of absorbances at 660 and 940 nm — the principle of the pulse oximeter.
- Electrochemistry Galvanic cells: identify an unknown metal Put metal strips into 0.100 M solutions of their salts, join pairs with a salt bridge and read the voltage; build a series of cells against reference metals, rank the metals, then compute the standard potential of an unknown metal X and identify it.
- Electrochemistry Two-point calibration of a pH meter and sample measurement A glass combination electrode with an unknown zero and slope: calibrate it with pH 4.01, 7.00 and 10.01 buffers, measure acetic acid, an ammonia buffer, a high-sodium caustic solution and an unknown buffer, then reveal the electrode to find which readings were pulled off by extrapolation or by the sodium error.
- Electrochemistry The zirconia sensor and the switch at λ = 1 Turn the engine mixture from lean to rich, record the voltage of a zirconia sensor and find the stoichiometric point; then change the sensor temperature and the yttria content and see what alters the reading.
- Electrochemistry Water by coulometric Karl Fischer titration Check the titrator with a water standard, then measure a dry solvent holding only 25 ppm of water and a wet one at 0.5 %. Change the generator current and the drift and find out when the result can be trusted and when the drift must be subtracted.
- Rates and equilibrium The cobalt chloride colour equilibrium: Le Chatelier’s principle In a tube of violet solution, pink [Co(H₂O)₆]²⁺ and blue [CoCl₄]²⁻ are in equilibrium. Add hydrochloric acid, water or silver nitrate, or dip it in hot or iced water; watch the colour change and explain each shift with Q and K.
- Rates and equilibrium The iodine clock: initial rates and activation energy Vary the amounts of potassium iodide and ammonium persulfate and time each beaker; find both orders and the rate constant from initial rates, then repeat at different bath temperatures and build an Arrhenius plot for the activation energy.
- Rates and equilibrium Measure the half-life of barium-137m with a Geiger counter Elute a few drops containing ¹³⁷ᵐBa from a ¹³⁷Cs/¹³⁷ᵐBa isotope generator, count them with a Geiger counter interval after interval, subtract the background, plot ln(count rate) against time and get the half-life — with its uncertainty — from the slope.
- Inorganic synthesis and qualitative analysis Cation qualitative analysis: identify an unknown With hydrochloric acid, hot water, ammonia, sodium hydroxide and a few confirmatory reagents, separate and confirm seven cations one by one and work out what an unknown contains.
- Inorganic synthesis and qualitative analysis Halogen displacement: identifying halogens by their hexane layer Add chlorine, bromine and iodine water to KCl, KBr and KI solutions, then extract with hexane: the colour of the hexane layer on top tells you which halogen is present. Finally, use the same trick to identify an unknown halide solution.
- Inorganic synthesis and qualitative analysis The four oxidation states of vanadium: a rainbow in one flask Add zinc powder to acidified ammonium vanadate and watch the solution run from yellow through green, blue and green to violet; then try tin, an iron(II) salt and potassium iodide, and use standard potentials to explain where each reducing agent stops.
- Separation and analysis Sulfate by gravimetry: ignite to constant mass Precipitate the sample’s sulfate as BaSO₄ — slowly, from a hot dilute solution — digest, filter and wash, then ignite and weigh repeatedly to constant mass and compute the sulfate content with the gravimetric factor. Nickel by dimethylglyoxime is available too.
- Separation and analysis Blood alcohol by headspace gas chromatography with an internal standard Separate ethanol from the 1-propanol internal standard on a polyethylene glycol capillary column, build an area-ratio calibration line from five calibrators, measure the ethanol in an unknown blood sample and decide whether it crosses the drink-driving and drunk-driving thresholds.