Chemistry Calculators — Molarity, Dilution & Stoichiometry

The dilution formula C1V1 = C2V2 means that the concentration of the initial (stock) solution multiplied by its volume equals the concentration of the final (diluted) solution multiplied by its volume.

It assumes the amount of solute remains constant during dilution - only solvent is added.

You can rearrange the formula to solve for any unknown variable:

C1 = (C2 x V2) / V1
V1 = (C2 x V2) / C1
C2 = (C1 x V1) / V2
V2 = (C1 x V1) / C2

Divide the actual yield (mass of product you obtained) by the theoretical yield (mass predicted by stoichiometry) and multiply by 100. A percent yield above 100% usually indicates impurities or measurement errors. Most real reactions yield 60—90% due to side reactions and losses.

Look up the atomic mass of each element on the periodic table, multiply by the number of atoms of that element in the formula, and sum all contributions. For example, H₂O has a molar mass of (2 × 1.008) + (1 × 16.00) = 18.016 g/mol. Our molar mass calculator automates this from any molecular formula.

pH is calculated as the negative logarithm (base 10) of the hydrogen ion concentration: pH = -log₁₀[H⁺]. For example, if [H⁺] = 0.001 M (10⁻³ mol/L), pH = -log(0.001) = 3.0. Lower pH means more acidic, higher means more basic (pH 7 is neutral). The reverse (pOH = -log[OH⁻]) gives alkalinity, and pH + pOH = 14 in water at 25°C. Our pH calculator instantly computes pH from concentration, and supports conversions between pH, [H⁺], and pOH for acids, bases, or buffers.

Molarity (M) is moles of solute per liter of solution (volume-based), while molality (m) is moles of solute per kilogram of solvent (mass-based). Molarity changes with temperature (volume expands/contracts), but molality stays constant. Molarity is common in reactions and dilutions; molality is preferred for colligative properties (boiling point elevation, freezing point depression). For example, 1 M NaCl is 1 mole NaCl per liter solution; 1 m NaCl is 1 mole per kg water. Our molarity to molality converter handles density adjustments and temperature effects for precise conversions.

The limiting reactant is the reagent that runs out first and determines how much product can form. Convert reactant amounts to moles, then compare to the balanced equation's mole ratio. For example, in 2H₂ + O₂ → 2H₂O, if you have 4 mol H₂ and 3 mol O₂, O₂ is limiting (needs 2 mol O₂ per 2 mol H₂, but you have excess H₂). Divide each reactant’s moles by its coefficient; the smallest ratio wins. Our limiting reactant calculator inputs reactant masses or moles, balances the equation automatically, and identifies the limiting reagent with theoretical yield.

Balancing ensures the same number of each atom on both sides. Start with the most complex molecule, adjust coefficients (never subscripts), balance metals first, then non-metals, oxygen last, hydrogen last. For example, C₃H₈ + O₂ → CO₂ + H₂O: balance C (3→3), H (8→4 H₂O), O (adjust O₂ to 5). Trial-and-error or algebraic method works. Our chemical equation balancer accepts unbalanced equations and instantly provides the balanced version with coefficients, plus step-by-step explanation for learning.