These ten calculators handle the arithmetic that comes up constantly at a chemistry bench or in a chemistry course: converting between mass and moles, making up or diluting a solution to a target concentration, expressing acidity, and working out how much product a reaction can actually yield. Each one uses the standard textbook equation rather than an approximation, so the value here is speed and freedom from arithmetic slips, not a shortcut around understanding the formula itself.
Calculators in this section
A theme runs underneath most of them: units, not the maths, are the usual source of error. Molarity and molality look similar but measure against different things — volume of solution versus mass of solvent — and mixing them up, or using a solution's total mass where a solvent's mass is needed, produces a wrong answer that still looks plausible. The same applies to molecular weight, where a formula for a hydrated salt or a diatomic gas needs the actual molecular formula, not a simplified one, to come out right.
The stoichiometry, limiting reactant and percent yield calculators work as a set rather than separately: a balanced equation's coefficients set the mole ratios, the limiting reactant determines the ceiling on product, and percent yield compares what was actually collected against that ceiling. Results here carry more decimal places than your original measurement usually justifies — rounding to the correct number of significant figures at the end is left to you.