Chemistry Equation Sheet

Formal charge VE - valence electrons BE - bonding electrons (in pairs) LPE - lone pair electrons Formal charge = VE - ½ BE - LPE Percent yield percent yield = actual mass of desired product theoretical mass of desired product Chemistry x 100% Equilibrium (rate forward = rate reverse) k R - ideal gas constant (8.3145 J · mol-1 · K-1) or 0.082 L · atm · K-1 · mol-1) F - Faraday’s constant (96,485 C/mol) Keq or Kc - equilibrium constant kforward - rate constant of forward reaction kreverse - rate constant of reverse reaction [A-D] - concentration of reactants and products A-D. a-d - stoichiometric coefficients Keq = kforward reverse aA + bB cC + dD [C]c[D]d Kc = [A]a[B]b Reaction quotient aA + bB → cC + dD Q= [C]c [D]d [A]a[B]b Q > Kc: Reaction nets reactants Q < Kc: Reaction nets products Q = Kc: Equilibrium Kc - equilibrium constant Q - reaction quotient [A-D] - concentration of reactants and products A-D. a-d - stoichiometric coefficients Kelvin Temperature K = oC + 273.15 K - temperature in Kelvin C - temperature in Celsius o Heat Q = mcΔT Q - heat m - mass c - specific heat ∆T - change in temperature Enthalpy of the reaction ΔH°rxn - enthalpy of reaction ΔHorxn = ΔHoproducts - ΔHoreactants ΔH°products - enthalpy of products ΔH°reactants - enthalpy of reactants Enthalpy of the reaction ΔHrxn - enthalpy of reaction ΔHrxn = ΔHbonds broken - ΔHbonds formed ΔHbonds broken - bond enthalpy of bonds broken ΔHbonds formed - bond enthalpy of bonds formed Gibbs free energy ΔG = ΔH - TΔS ΔG - change in Gibbs free energy ΔH - change in enthalpy T - temperature ΔS - change in entropy Gibbs free energy of a reaction ΔG°rxn - Gibbs free energy change of the reaction ΔGorxn = ΔGo products - ΔGo reactants ΔG°products - sum of products’ free energy of formation ΔG°reactants - sum of reactants’ free energy of formation Gibbs free energy of a reaction ΔGrxn - Gibbs free energy of the reaction ΔG°rxn - Gibbs free energy of the reaction under standard conditions R - ideal gas constant T - temperature Q - Reaction quotient ΔGrxn = ΔGo rxn + RTlnQ Gibbs Free energy of a reaction at equilibrium Chemistry ΔGorxn = -RTlnKeq R - ideal gas constant (8.3145 J · mol-1 · K-1) or 0.082 L · atm · K-1 · mol-1) F - Faraday’s constant (96,485 C/mol) ΔG°rxn - Gibbs free energy of the reaction under standard conditions R - ideal gas constant T - temperature Keq - equilibrium constant van der Waals equation an2 (P + V2 )(V - nb) = nRT P - pressure V - Volume n - moles of gas R - ideal gas constant T - Temperature a - the attractive forces factor b - the volume factor Dalton’s law of partial pressure Pgas = Xgas Ptotal Pgas - partial pressure of a gas Xgas - mole ratio of a gas Ptotal - total pressure in a container Boyle’s law PV = constant P - pressure V - volume Charles’s law V = constant T V - volume T - temperature Gay-Lussac’s law P = constant T P - pressure T - temperature Molality moles of solute mol molality (m) = kilograms of solvent = kg Molarity moles of solute mol molarity (M) = liters of solution = L Raoult’s law P = XAPAO P - vapor pressure of the solution XA - mole fraction of the solvent PA° - vapor pressure of the pure solvent Boiling point elevation ΔTb - magnitude of boiling point elevation i - van ‘t Hoff factor Kb - boiling point elevation constant m - molality ΔTb = iKbm Freezing point depression Chemistry R - ideal gas constant (8.3145 J · mol-1 · K-1) or 0.082 L · atm · K-1 · mol-1) ΔTf - magnitude of freezing point depression i - van ‘t Hoff factor Kf - freezing point depression constant m - molality ∆Tf = iKfm Osmotic pressure Π - osmotic pressure i - van ‘t Hoff factor M - molarity R - ideal gas constant T - temperature Π = iMRT F - Faraday’s constant (96,485 C/mol) Arrhenius equation k = Ae k - rate constant A - frequency factor constant Ea - activation energy R - ideal gas constant T - temperature -Ea /RT Reaction rate rate - reaction rate k - rate constant [A] and [B] - concentration of reactants x and y - order of reaction with respect to each reactant rate = k[A]x[B]y Ionization constant of water KW = [H3O+][OH-] = 1 x 10-14 at 25oC Kw - ionization constant of water [H₃O+] and [OH-] - concentrations of hydronium and hydroxide ions in water pH pH = -log[H3O+] pOH pOH = -log[OH-] Henderson-Hasselbalch equation [A-] pH = pKa + log [HA] pH - pH of the solution pKa - pKa of acid [HA] - concentration of acid [A-] - concentration of conjugate base Equivalence point of a titration aMaVa = bMbVb a and b - number of dissociable protons or hydroxide ions M - molarity of acid or base V - volume of acid or base Standard cell potential Eocell = Eocathode - Eo anode Eocell - standard cell potential Eocathode - electric potential at cathode Eoanode - electric potential at anode Nernst equation Eocell - standard cell potential Chemistry E RT = Eo cell - nF lnQ E cell cell = Eo cell - 0.059 log10Q n R - ideal gas constant (8.3145 J · mol-1 · K-1) or 0.082 L · atm · K-1 · mol-1) F - Faraday’s constant (96,485 C/mol) E cell - cell potential R - ideal gas constant T - temperature n - moles of electrons F - Faraday’s constant Q - reaction quotient Electroplating nF = lt n - moles of electrons F - Faraday’s constant t - time I - current Gibbs free energy of an electrochemical cell ΔGo = -nFEo cell ΔG° - Gibbs free energy under standard conditions Eocell - standard cell potential n - moles of electrons F - Faraday’s constant Specific rotation α [α] = cℓ Organic Chemistry R - ideal gas constant (8.3145 J · mol-1 · K-1) or 0.082 L · atm · K-1 · mol-1) F - Faraday’s constant (96,485 C/mol) [α] - specific rotation α - observed rotation c - concentration ℓ - length of the polarimeter tube