Chemistry

  • Soap Lye Calculator
    Calculate the exact grams of NaOH lye and water needed for cold-process soap from your oil weight, SAP value, superfat percentage and water ratio.
  • Wavelength to Wavenumber Calculator
    Convert wavelength (nm, µm, mm, cm, m) to wavenumber in cm⁻¹ instantly. Uses ν̃ = 1/λ(cm) = 10⁷/λ(nm) for spectroscopy and IR analysis.
  • Average Reaction Rate Calculator
    Calculate the average rate of a chemical reaction from concentration change over time, with stoichiometric coefficient correction for reactants or products.
  • Vapor Pressure Lowering Calculator
    Calculate vapor pressure lowering (Δp) of a solution using Raoult's law: Δp = x_solute × p°_solvent. Enter moles of solute, solvent and pure pressure.
  • Specific Rotation Calculator
    Calculate specific rotation [α] from observed rotation, path length, and concentration using [α] = α/(l·c). Free polarimetry chemistry tool.
  • Enantiomeric Excess Calculator
    Calculate enantiomeric excess (%ee) from R and S enantiomer amounts. Uses %ee = |R − S| / (R + S) × 100 for chiral purity in chemistry.
  • Henry's Law Calculator
    Calculate dissolved gas concentration with Henry's Law: C = kH × P. Enter the Henry's law constant and partial pressure to find solubility in mol/L.
  • PPB Calculator
    Calculate concentration in parts per billion (ppb) from mass of solute and mass of solution. Also shows ppm and percent. Free, instant chemistry tool.
  • Common-Ion Effect Calculator
    Convert Ksp to molar solubility for any salt MxAy. Enter Ksp and stoichiometric coefficients to find s and ion concentrations in mol/L.
  • Molecular Formula Calculator
    Find the molecular formula from an empirical formula. Enter empirical formula mass and molar mass to get the whole-number multiple n and molecular formula.
  • Weight Percent to Molarity Calculator
    Convert weight percent (wt%) to molarity (mol/L) using solution density and solute molar mass. Free chemistry concentration calculator with the formula explained.
  • Percent by Mass of Element in Compound Calculator (with Mass in Grams)
    Find the mass of an element within a compound sample. Enter atoms, atomic mass, molar mass and total mass to get grams and percent by mass.
  • Solubility Product (Ksp) Calculator
    Calculate the solubility product constant (Ksp) from molar solubility for any salt AxBy using Ksp = (x·s)^x · (y·s)^y. Free chemistry tool.
  • Gibbs Free Energy from Cell Potential Calculator
    Calculate Gibbs free energy change (ΔG) from cell potential using ΔG = −nFE. Enter moles of electrons, voltage, and Faraday constant to get ΔG in kJ/mol.
  • Standard Cell Potential Calculator
    Calculate the standard cell potential E°cell of an electrochemical cell from the cathode and anode standard reduction potentials using E°cell = E°cathode − E°anode.
  • Limiting Reactant Calculator
    Find the limiting reactant in any chemical reaction. Enter moles and stoichiometric coefficients to see which reagent runs out first and the excess remaining.
  • Molar Volume of Gas Calculator
    Calculate the molar volume of an ideal gas (L/mol) from temperature and pressure using Vm = RT/P. STP gives ≈ 22.414 L/mol at 1 atm.
  • Dalton's Law Partial Pressure Calculator
    Calculate the partial pressure of a gas from its mole fraction and the total pressure using Dalton's Law: Pᵢ = xᵢ × P_total. Free and instant.
  • Photon Energy from Frequency Calculator
    Calculate photon energy from its frequency using E = hf. Enter frequency in Hz to get energy in joules and electronvolts instantly.
  • pH Buffer Preparation Calculator
    Calculate how much weak acid and conjugate base to mix for a target pH buffer using the Henderson-Hasselbalch equation. Get ratio, concentration & moles.
  • Percent Dilution Calculator
    Calculate the final percent concentration after adding diluent. Uses C2 = C1·V1/(V1+V_added) to find diluted strength, total volume, and dilution factor.
  • Moles to Grams to Atoms Calculator
    Convert mass to moles to particles fast. Enter grams and molar mass to find the number of atoms or molecules using Avogadro's number.
  • Integrated Rate Law Calculator
    Solve zero, first, and second order integrated rate laws. Enter [A]₀, rate constant k, and time t to find concentration [A] and half-life instantly.
  • Van't Hoff Equation Calculator
    Compute a new equilibrium constant K2 from K1, ΔH and two temperatures using the Van't Hoff equation: ln(K2/K1) = -(ΔH/R)(1/T2 - 1/T1).

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