#moles

Chemical reaction-stoichiometry maths as an API, computed locally and deterministically. The limiting-reagent endpoint takes two reactants with their amounts in moles and their balanced-equation coefficients and finds which one runs out first — the limiting reagent — by comparing the moles/coefficient ratio (the reaction extent), and returns how much of the excess reagent is left over. The yield endpoint computes the theoretical yield of a product, in moles and grams, from the limiting reagent and the product's stoichiometric coefficient and molar mass, n_product = n_limiting·(coeff_product/coeff_limiting), and — given the actual yield — the percent yield. The mole-mass endpoint converts between moles, mass and the number of particles for a given molar mass, using moles = mass / molar_mass and N = moles · Avogadro's number (6.02214076e23). Amounts are in moles, masses in grams and molar masses in g/mol. Everything is computed locally and deterministically, so it is instant and private. Ideal for chemistry-education, lab, pharmaceutical and chemical-engineering app developers, reaction-planning and yield tools, and STEM teaching. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is reaction stoichiometry; for a compound's molar mass from its formula use a molar-mass API and for solution concentrations a dilution API.

api.oanor.com/stoichiometry-api

Molar-mass and stoichiometry maths as an API, computed locally and deterministically. The molarmass endpoint parses any chemical formula — with parentheses, square brackets and hydrate dots, such as Ca(OH)2, [Fe(CN)6]3 or CuSO4·5H2O — against the IUPAC conventional atomic weights and returns the molar mass in grams per mole, the total atom count and the per-element breakdown with each element's mass contribution and mass percent. The convert endpoint moves between moles, mass in grams and number of molecules for a formula, using n = mass ÷ M = molecules ÷ Nₐ with Avogadro's number. The percent endpoint gives the percent composition by mass and, for a given sample mass, the mass of each element it contains. The formula is parsed locally, so it works for any valid formula, not just compounds in a database, and is instant and private. Ideal for chemistry-education, laboratory, pharmaceutical and science app developers, stoichiometry and lab-prep tools, and STEM teaching. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This computes molar mass from a formula; for compound database lookup use a chemistry API and for element properties an elements API.

api.oanor.com/molarmass-api