Chemistry Equations and Constants

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AP Chemistry Equations and Constants

  • Definitions of symbols used in the test:

    • L, mL = liter(s), milliliter(s)

    • mm Hg = millimeters of mercury

    • g = gram(s)

    • J, kJ = joule(s), kilojoule(s)

    • nm = nanometer(s)

    • V = volt(s)

    • atm = atmosphere(s)

    • mol = mole(s)

  • Atomic Structure:

    • Energy equation: E = hv = frequency iv A = wavelength

    • Planck's constant, h = 6.626x10^-34 Js

    • Speed of light, C = 2.998 x 10^8 m/s

    • Avogadro's number = 6.022 x 10^23 mol^-1

    • Electron charge, e = -1.602 x 10^-19 coulomb

  • Equilibrium:

    • Equilibrium constant equation: K = [A]"[B]" / [C]"[D]"

    • Equilibrium constants:

      • K (molar concentrations)

      • Kp (gas pressures)

      • K (weak acid)

      • Kb (weak base)

      • Kw (water)

    • Kw = [H+][OH-] = 1.0 x 10^-14 at 25°C

    • pH = log[H+], pOH = -log[OH-]

    • 14 = pH + pOH

  • Kinetics:

    • Rate equation: In[A] - In[A]o = kt

    • Rate constant: k

    • Half-life: t1/2 = 0.693 / k

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Gases, Liquids, and Solutions:

  • Gas equation: PV = nRT

  • Volume equation: V = nRT / P

  • Total moles equation: XA = moles A / n

  • Number of moles equation: n = m / M

  • Density equation: D = m / V

  • Kinetic energy equation: KE = 1/2mv^2

  • Velocity equation: V = √(2KE / m)

  • Absorbance equation: A = εbc

  • Molarity equation: M = moles of solute / liters of solution

  • Gas constant, R = 8.314 J mol^-1 K^-1

  • Conversion between Celsius and Kelvin: K = °C + 273

  • Conversion between Celsius and Fahrenheit: °F = (9/5)°C + 32

  • Conversion between Fahrenheit and Kelvin: K = (°F - 32) / (9/5)

Thermochemistry/Electrochemistry:

  • Heat equation: q = mcΔT

  • Specific heat capacity equation: C = q / (mΔT)

  • Standard entropy equation: ΔS° = S°(products) - S°(reactants)

  • Standard enthalpy equation: ΔH° = H°(products) - H°(reactants)

  • Standard free energy equation: ΔG° = G°(products) - G°(reactants)

  • Standard reduction potential equation: E° = E°(products) - E°(reactants)

  • Faraday's constant, F = 96,485 coulombs per mole

  • Charge equation: q = -nFE°

  • Time equation: t = q / I

  • Volt equation: 1 volt = 1 cou