Chemistry Tools
Interactive calculators for Cambridge Secondary Chemistry — moles, pH, titration, electrolysis and more.
Uses the equation: n = m / M (moles = mass ÷ molar mass)
Percentage Yield
Atom Economy
Uses: pH = −log₁₀[H⁺] | [H⁺] = 10⁻ᵖᴴ
Uses: C = n / V where C = mol/dm³, n = mol, V = dm³
Convert: mass → concentration
Percentage yield = (actual / theoretical) × 100
Atom Economy
Atom economy = (Mr of desired product / sum of all product Mr values) × 100
Theoretical yield from moles
C₁V₁ = C₂V₂ (adjusted for mole ratio). All volumes in cm³.
Q = I × t | moles of electrons = Q / F (F = 96,500 C/mol) | moles of product = moles e⁻ / n
Find current or time
At RTP: V = n × 24 dm³/mol | At STP: V = n × 22.4 dm³/mol
Ideal Gas Law: PV = nRT
Enter a chemical formula to calculate Mr. Supports: H₂O → H2O, H₂SO₄ → H2SO4, Ca(OH)₂ → Ca(OH)2
Percentage composition
Empirical formula from % composition
Rf = distance moved by spot / distance moved by solvent front (always 0–1, no units)