Choose a mode and enter the known values
Select a calculation from Calculation mode, complete the displayed inputs, and select Calculate. The calculator supports pH / pOH / [H+] / [OH-], Molarity, Dilution (C1V1 = C2V2), Molar mass, Stoichiometry & limiting reagent, Percent yield, Solution preparation, Beer-Lambert law, and Specific heat (q = mcΔT).
- For pH, choose one item from Known value: pH, pOH, [H+] (mol/L), or [OH-] (mol/L), then enter one value.
- For Molarity, choose Molarity (M), Moles (n), or Volume from Solve for. Enter the other two quantities. If you have mass, select I have mass instead of moles and enter Mass (g) and Chemical formula. Choose mL or L when Volume unit is shown.
- For Dilution, choose V2 (final volume), C1 (initial concentration), V1 (initial volume), or C2 (final concentration). Enter the other three values using matching concentration units and matching volume units; this mode does not convert between units.
- For Molar mass, enter Chemical formula.
- For Stoichiometry & limiting reagent, enter the coefficients, formulas, and amount for the product and at least one reactant. Amounts use g or mol. Select Add a second reactant (to check for a limiting reagent) when needed, and supply a correctly balanced equation.
Complete the mode-specific inputs
- Percent yield: choose Percent yield, Actual yield, or Theoretical yield from Solve for, then enter the other two fields. Actual yield and Theoretical yield must use the same unit. Percent yield (%) has no unit selector, so matching units are your responsibility. Positive values are accepted, and the result is not capped at 100%.
- Solution preparation: choose Mass to weigh out, Resulting molarity, or Final volume needed. Enter Chemical formula (solute) and the other two quantities, including Target molarity (mol/L) and Target volume. Use Volume unit to choose mL or L. This assumes a pure, dry solute dissolved to the stated final volume, not dilution from a stock solution.
- Beer-Lambert law: choose Absorbance (A), Concentration (c, mol/L), Path length (l, cm), or Molar absorptivity (ε) from Solve for, then provide the other three values. Molar absorptivity is supplied by you; the calculator does not look it up. It uses
A = ε x c x l. - Specific heat: choose Heat energy (q), Mass (m), Specific heat capacity (c), or Temperature change (ΔT) from Solve for. Enter the other three values with Heat energy, q (J), Mass, m (g), Specific heat capacity, c (J/(g·°C)), and Temperature change, ΔT (°C). Heat energy and temperature change accept signed values; mass and specific heat capacity must be positive.
The Formulas Used
- pH:
pH = -log10[H+],pOH = -log10[OH-],pH + pOH = 14(at 25 °C),[H+][OH-] = 1.0 x 10^-14. - Molarity:
M = moles of solute / liters of solution. - Dilution:
C1 x V1 = C2 x V2. - Molar mass: sum of (atom count x standard atomic weight) for every element in the parsed formula.
- Stoichiometry: mole ratio from balanced-equation coefficients,
moles of product = moles of reactant x (coefficient of product / coefficient of reactant), with the smaller of two reactants' possible product amounts identifying the limiting reagent. - Percent yield:
percent yield = (actual yield / theoretical yield) x 100. - Solution preparation:
mass = molarity x volume(L) x molar mass. - Beer-Lambert law:
A = epsilon x c x l. - Specific heat:
q = m x c x ΔT.
Run, review, or save the result
Select Calculate to display the result under Formula & steps and Assumptions. Use Reset to clear mode-panel inputs and selections, hide the result, and restore the initial selections. Copy result copies the plain-text result when clipboard access succeeds; otherwise select and copy it manually. Download result (.txt) downloads the result as a text file.
Supported Formula Syntax and Units
The parser accepts element symbols, integer or decimal counts, nested parentheses or brackets such as Ca(OH)2 and Al2(SO4)3, and dot or asterisk hydrates such as CuSO4.5H2O. It does not accept unsupported formula characters or notation outside this syntax, and it does not identify compounds from names. Molar mass is reported in g/mol using standard conventional atomic weights.
Units and calculation limits
- Volume: mL or L where the interface provides a volume-unit selector, including molarity and solution preparation.
- Stoichiometry amount: g or mol.
- Beer-Lambert law: Absorbance (A), Concentration (c, mol/L), Path length (l, cm), and user-supplied Molar absorptivity (ε).
- Specific heat: Heat energy, q (J), Mass, m (g), Specific heat capacity, c (J/(g·°C)), and Temperature change, ΔT (°C).
- Dilution: matching concentration units and matching volume units as entered.
Stoichiometry and Limiting-Reagent Assumptions
Supply a correctly balanced equation's coefficients and formulas; the calculator does not balance or verify it. With one reactant, that reactant is treated as the only limiting factor and unentered reagents as unlimited. With two reactants, the calculator compares their possible product amounts and reports the smaller amount and corresponding limiting reagent. It assumes completion according to the supplied coefficients, 100% conversion of the limiting reagent, and unlimited availability of any unentered reagent.
Validation and Limitations
Numeric entries must use the accepted number syntax and stay within the absolute limit of 1e12. Fields that must be positive reject zero and negative values; other fields use their implemented non-negative or unrestricted checks. Unknown element symbols, unbalanced parentheses, unsupported formula characters, and invalid numbers produce errors. The calculator does not identify chemicals, balance or look up equations, or provide laboratory safety guidance.
Privacy for Calculations
The calculation runs in the browser-side JavaScript, and the calculation itself does not send entered values through a network request.
Frequently Asked Questions
What chemistry calculations does this tool support?
Nine modes: pH/pOH, molarity, dilution, molar mass from a chemical formula, stoichiometry (with an optional limiting-reagent comparison), percent yield, solution preparation, the Beer-Lambert law, and specific heat (q = mcΔT). Choose a mode, enter the known values, and calculate.
What chemical formulas can the molar mass parser read?
Standard element symbols with integer or decimal subscripts, nested parentheses or brackets such as Ca(OH)2 or Al2(SO4)3, and hydrates written with a dot or asterisk, such as CuSO4.5H2O. It uses standard atomic weights for naturally occurring element mixtures; it does not identify an unknown compound from a name or resolve isotope-specific masses.
How does the stoichiometry mode handle a limiting reagent?
Enter the balanced-equation coefficients and formulas for one or two reactants and the product, plus the amount of each reactant you have. If you enter both reactants, the tool computes how much product each could produce alone and reports the smaller amount and the corresponding limiting reagent, assuming the reaction goes to completion exactly as entered.
Does this tool identify unknown chemicals or balance equations for me?
No. You must supply valid chemical formulas and, for stoichiometry, a correctly balanced set of coefficients yourself. This tool does not identify an unknown substance, does not balance or look up reaction equations, and does not provide laboratory safety guidance - it performs deterministic arithmetic on the values and formulas you provide.