Chemistry Formulas

Buffer Capacity Formula

Calculate buffer capacity using β = ΔB/ΔpH. Learn how to measure a buffer solution's resistance to pH change with worked examples.

Born-Haber Cycle Formula

The Born-Haber cycle uses Hess's law to calculate the lattice energy of ionic compounds from thermochemical data. Explains ionic crystal stability.

Debye-Hückel Limiting Law

Reference for the Debye-Huckel limiting law predicting activity coefficients of ions in dilute electrolyte solutions and why real solutions deviate.

Kohlrausch's Law of Independent Migration

Kohlrausch's law describes how molar conductivity of a strong electrolyte varies with concentration. Used to determine Ka of weak acids.

Langmuir Adsorption Isotherm

Langmuir isotherm: theta = (K*c)/(1 + K*c). Model the fraction of surface covered by adsorbed molecules at equilibrium concentration.

Ostwald's Dilution Law

Ostwald's dilution law relates the degree of dissociation of a weak electrolyte to its concentration and dissociation constant Ka.

Specific Rotation Formula (Optical Activity)

The specific rotation formula measures the optical activity of chiral molecules. Used in pharmaceutical purity testing and sugar analysis.

Van der Waals Equation

The Van der Waals equation corrects the ideal gas law for real gases by accounting for molecular size and intermolecular attractions.

Dalton's Law of Partial Pressures

Reference for Dalton's Law of Partial Pressures P_total = P1+P2+...+Pn. Calculate total gas mixture pressure from component partial pressures with examples.

Graham's Law of Effusion

Reference for Graham's law: gas effusion rate is inversely proportional to the square root of molar mass. With step-by-step examples and applications.

Ionic Strength Formula

Ionic strength formula I = ½Σcᵢzᵢ² quantifies ion concentration in solutions. Used in electrochemistry, activity coefficient calculations, and buffer design.

Arrhenius Equation

Reference for the Arrhenius equation k = A*exp(-Ea/RT). Shows how reaction rate constants change with temperature, with activation energy and worked examples.

Beer-Lambert Law

The Beer-Lambert law A = elc relates light absorbance to concentration for spectrophotometry analysis. Learn with examples.

Bond Energy Formula

Bond energy measures the strength of a chemical bond. Learn how to calculate enthalpy changes using bond energies with worked examples.

Clausius-Clapeyron Equation

The Clausius-Clapeyron equation relates vapor pressure changes to temperature and heat of vaporization. Learn with examples.

Colligative Properties Formulas

Colligative properties depend on solute concentration, not identity. Learn boiling point elevation and freezing point depression formulas.

Concentration Formulas (Molarity and Molality)

Reference for molarity (M = mol/L), molality (m = mol/kg), mass percent, and ppm. Includes unit conversions and examples for chemistry lab and pharmacy.

Electrochemistry Formulas

Reference for electrochemistry formulas: cell potential, Nernst equation, Gibbs free energy, and Faraday's laws for electrolysis and battery design.

Enthalpy Formula

The enthalpy formula ΔH = ΔU + PΔV relates heat change to internal energy and work. Learn thermochemistry with worked examples.

Equilibrium Constant Formula

The equilibrium constant Keq expression relates product and reactant concentrations at equilibrium. Learn chemical equilibrium with examples.

Gibbs Free Energy Formula

Calculate Gibbs free energy with G = H - TS to predict if a chemical reaction will occur spontaneously. Includes worked examples.

Henderson-Hasselbalch Equation

The Henderson-Hasselbalch equation calculates pH of buffer solutions from pKa and concentration ratios. Essential for chemistry.

Hess's Law Formula

Reference for Hess's law: total enthalpy change equals the sum of individual step enthalpies regardless of pathway. Includes worked examples and Hess cycles.

Lewis Structure Rules

Learn the systematic rules for drawing Lewis dot structures. Count valence electrons, apply the octet rule, and handle exceptions.

Molality Formula

Molality (m) equals moles of solute divided by kilograms of solvent. Used for colligative properties like boiling point elevation.

Molar Mass Formula

Reference for molar mass in g/mol by summing atomic masses. Includes examples for H2O (18.02 g/mol), glucose (180.16), NaCl (58.44), and mole conversions.

Molarity and Dilution Formulas

Molarity formula M = n/V (moles per liter) and dilution equation M1V1 = M2V2. Covers solution concentration, dilution factors, and worked examples with units.

Nernst Equation

Reference for E = E0 - (RT/nF) x ln(Q) Nernst equation. Calculates cell potential at non-standard conditions for batteries, corrosion, and biochemistry.

Osmolarity Formula

Osmolarity measures total solute particle concentration in a solution. Calculated as n × M, where n is dissociation factor and M is molarity.

Percent Yield Formula

The percent yield formula compares actual product obtained to theoretical maximum. Essential for chemistry lab calculations.

Raoult's Law

Reference for Raoult's law P = x*P0 for vapor pressure of ideal solutions from mole fractions. Covers partial pressures, deviations, and worked examples.

Rate Law Formula

The rate law formula rate = k[A]^n describes how reactant concentration affects reaction speed. Learn chemical kinetics with examples.

Reaction Rate Formula

Calculate the rate of a chemical reaction as the change in concentration over time. Includes rate laws and worked examples.

Stoichiometry

Reference for stoichiometry: use mole ratios from balanced equations to calculate masses. Covers molar mass, limiting reagent, percent yield, and examples.

Titration Endpoint Formula

The titration formula C₁V₁ = C₂V₂ calculates unknown concentrations by reacting an acid with a base to reach the equivalence point.

Vapor Pressure (Clausius-Clapeyron Equation)

The Clausius-Clapeyron equation relates vapor pressure to temperature. Learn how to calculate vapor pressure changes with examples.

Arrhenius Equation (Activation Energy)

Reference for the Arrhenius equation k = Ae^(-Ea/RT). Covers activation energy in kJ/mol, pre-exponential factor, and the 10°C temperature-doubling rule.

Henry's Law

Calculate gas solubility from pressure using Henry's Law: C = kH × P. Explains soda carbonation, scuba decompression sickness, and oxygen in blood plasma.

Osmotic Pressure Formula

Reference for osmotic pressure pi = iMRT covering van't Hoff factor, molarity, and temperature. Applications in IV fluids, dialysis, and reverse osmosis.

Avogadro's Number

Avogadro's number (6.022 × 10²³) defines how many particles are in one mole. Learn to convert between moles and individual atoms or molecules.

Boyle's Law

Boyle's law P₁V₁ = P₂V₂ describes how gas pressure and volume are inversely related at constant temperature. Includes worked examples.

Charles's Law

Charles's law V₁/T₁ = V₂/T₂ shows how gas volume changes with temperature at constant pressure. Step-by-step examples included.

Dilution Formula

The dilution formula M₁V₁ = M₂V₂ calculates the new concentration when a solution is diluted. Essential for lab work and solution preparation.

Ideal Gas Law

The ideal gas law PV = nRT relates pressure, volume, temperature, and amount of gas. Master gas calculations with worked examples.

Molarity Formula

The molarity formula M = moles/volume calculates the concentration of a solution. Essential for chemistry lab work and solution preparation.

Mole Calculation Formula

The mole formula n = m/M converts between mass and moles using molar mass. Fundamental for all chemistry stoichiometry calculations.

Percent Composition Formula

The percent composition formula calculates the mass percentage of each element in a compound. Essential for chemical analysis and empirical formulas.

pH Formula

The pH formula pH = -log[H⁺] measures the acidity or basicity of a solution. Learn to calculate pH and hydrogen ion concentration with examples.

Specific Heat Formula

The specific heat formula Q = mcΔT calculates the heat energy needed to change the temperature of a substance. Includes worked examples with common materials.