| Concept | Formula | Notes |
|---|---|---|
| Density | ρ = m / V | Mass per unit volume. |
| Moles | n = m / M | Mass over molar mass. |
| Avogadro’s number | N = n NA | NA = 6.022×10²³. |
| Percent yield | % = (actual / theoretical) × 100 | Reaction efficiency. |
| Percent error | % = |exp − true| / true × 100 | Accuracy measure. |
| Concept | Formula | Notes |
|---|---|---|
| Molarity | M = n / V | Moles per liter. |
| Molality | m = n / (kg solvent) | Temperature‑independent. |
| Mole fraction | χ = nᵢ / nₜ | Dimensionless. |
| Dilution | M₁V₁ = M₂V₂ | Concentration change. |
| Raoult’s law | P = χ P° | Ideal solutions. |
| Freezing point depression | ΔTf = iKfm | Colligative property. |
| Osmotic pressure | π = iMRT | Semipermeable membranes. |
| Concept | Formula | Notes |
|---|---|---|
| Ideal gas law | PV = nRT | Universal gas relation. |
| Boyle’s law | P₁V₁ = P₂V₂ | Constant T. |
| Charles’s law | V₁/T₁ = V₂/T₂ | Constant P. |
| Dalton’s law | Pₜ = ΣPᵢ | Partial pressures. |
| Gas density | ρ = PM / RT | M = molar mass. |
| Graham’s law | r₁/r₂ = √(M₂/M₁) | Effusion rates. |
| Concept | Formula | Notes |
|---|---|---|
| Heat | q = mcΔT | Temperature change. |
| Work | w = −PΔV | Expansion work. |
| First law | ΔE = q + w | Energy conservation. |
| Gibbs free energy | ΔG = ΔH − TΔS | Spontaneity. |
| Equilibrium relation | ΔG° = −RT ln K | Standard conditions. |
| Concept | Formula | Notes |
|---|---|---|
| Equilibrium constant | K = Π(products)/Π(reactants) | Concentration or pressure. |
| Reaction quotient | Q same form as K | Direction prediction. |
| Kp–Kc relation | Kp = Kc(RT)^{Δn} | Gas reactions. |
| Concept | Formula | Notes |
|---|---|---|
| pH | pH = −log[H⁺] | Acidity. |
| pOH | pOH = −log[OH⁻] | Basicity. |
| Kw | [H⁺][OH⁻] = 1×10⁻¹⁴ | At 25°C. |
| Ka | Ka = [H⁺][A⁻]/[HA] | Weak acids. |
| Henderson–Hasselbalch | pH = pKa + log([A⁻]/[HA]) | Buffers. |
| Concept | Formula | Notes |
|---|---|---|
| Cell potential | E° = E°cath − E°an | Reduction potentials. |
| Free energy | ΔG° = −nFE° | n = electrons. |
| Nernst equation | E = E° − (0.0592/n) log Q | At 25°C. |
| Concept | Formula | Notes |
|---|---|---|
| Rate law | rate = k[A]^m[B]^n | Experimentally determined. |
| Arrhenius equation | k = A e^{−Ea/RT} | Temperature dependence. |
| 1st‑order | ln([A]ₜ/[A]₀) = −kt | Half‑life: 0.693/k. |
| 2nd‑order | 1/[A]ₜ = 1/[A]₀ + kt | Rate ∝ [A]². |
| Concept | Formula | Notes |
|---|---|---|
| Photon energy | E = hν = hc/λ | Light quantization. |
| de Broglie wavelength | λ = h/(mv) | Wave–particle duality. |
| Bohr levels | Eₙ = −2.18×10⁻¹⁸ (1/n²) | Hydrogen atom. |