Playground ·
Reaction–diffusion
The Gray–Scott model — two imaginary chemicals that spread and react — grows coral, fingerprints and dividing cells from a few drops.
Chemistry
Chemistry for makers and engineers.
Exploration ·
Why sourdough rises
A jar of flour and water raises a loaf with no packet of yeast. Follow it from the microbes in the starter, through temperature, time, water and gluten, to the oven — with the sourdough, bread and artisan-bread tools open beside the text.
Tool ·
Ocean lab
Predict tides from NOAA harmonic constituents and check them against NOAA's own predictions; solve the wave dispersion relation, grow wind waves, shoal and break them; compute TEOS-10 seawater properties with a T–S diagram and CTD profiles; work out Coriolis, Ekman and geostrophic currents; and plot NDBC buoy observations.
Tool ·
Chemistry: formulas and the periodic table
Molar mass and percent composition from any formula (hydrates, ions, nested brackets), mass ↔ moles ↔ particles, empirical formulas, an equation balancer that handles ionic and redox equations, an interactive periodic table, and electrochemistry: galvanic cell EMF from standard electrode potentials and Faraday's law for plating and corrosion.
Tool ·
Isotope patterns and exact mass
Monoisotopic, average, and nominal mass for any formula; the isotope distribution as a stick spectrum at unit or fine resolution; m/z for common ESI adducts; and ppm mass error.
Tool ·
Molecule viewer (SMILES)
Type a SMILES string, a molecular formula or a name (about 630 molecules built in, plus PubChem search) to draw the 2D structure and get the formula, masses, rings, H-bond donors and acceptors, rotatable bonds, TPSA, cLogP and the Lipinski and Veber rules — plus, with RDKit in WebAssembly, canonical SMILES, InChI/InChIKey, exact descriptors, SMARTS substructure search and fingerprint similarity. Load a protein from the Protein Data Bank by ID (1A3N haemoglobin, 4INS insulin) in 3-D and export it as an STL for printing.
Tool ·
Solutions and lab maths
Make up solutions by weight, convert between molarity, % w/v, % w/w, ppm, molality and normality, plan dilutions and serial dilutions, calculate pH, design buffers, solve the ideal gas law and limiting-reagent problems, work out osmolarity and tonicity (van 't Hoff factor, permeant solutes), and do the available-chlorine arithmetic for disinfectant tablets.
Tool ·
Spectroscopy and calibration curves
Beer–Lambert solver with absorbance ↔ transmittance, a calibration-curve fitter (linear, through zero, or quadratic) with R², LOD/LOQ and back-calculated unknowns, and light conversions between wavelength, wavenumber, frequency, and photon energy with the visible colour.
Tool ·
Thermochemistry
Reaction enthalpy, entropy and Gibbs free energy from standard formation data, with ΔG and K against temperature, Hess's law solved automatically, ΔG° ↔ K and van 't Hoff, calorimetry, and bond-enthalpy estimates.
Tool ·
Titration curves
Simulate acid–base titration curves exactly for strong, weak, polyprotic, and mixed acids and bases, find equivalence and half-equivalence points and buffer regions, choose an indicator by titration error, and analyse your own pH-meter data by derivative and Gran plots.