balance an equation.

Type a chemical equation. StoichBalance solves the balance as a null-space problem on the element matrix — exact rational Gaussian elimination, scaled to the smallest whole-number coefficients, then re-verified element by element (H2 + O2 → H2O comes back as 2, 1, 2). Supply reactant amounts (moles or grams) and it computes the limiting reagent, the extent of reaction, and theoretical product yields. Real linear algebra, no lookup tables, no GPU.