Chemistry Equations & Constants Throughout the test the following symbols have the definitions specified unless otherwise noted. L, mL g nm atm = = = = liter(s), milliliter(s) gram(s) nanometer(s) atmosphere(s) mm Hg J, kJ V mol = = = = millimeters of mercury joule(s), kilojoule(s) volt(s) mole(s) ATOMIC STRUCTURE E = energy ν = frequency λ = wavelength E = hν c = λν Planck’s constant, h = 6.626 × 10−34 J s Speed of light, c = 2.998 × 108 m s−1 Avogadro’s number = 6.022 × 1023 mol−1 Electron charge, e = −1.602 × 10−19 coulomb EQUILIBRIUM Kc = [C] c[D] d , where a A + b B R cC+dD [A]a [B]b c Kp = (PC) (PD ) Kp (gas pressures) (PA )a (PB )b + Equilibrium Constants Kc (molar concentrations) d Ka (weak acid) Kb (weak base) - Ka = [H ][A ] [HA] Kb = [OH - ][HB+ ] [B] Kw (water) Kw = [H+][OH−] = 1.0 × 10−14 at 25°C = Ka × K b pH = −log[H+], pOH = −log[OH−−] 14 = pH + pOH pH = pKa + log [A- ] [HA] pKa = −logKa , pKb = −logKb KINETICS ln[A] t − ln[A] 0 = − kt 1 - 1 [A ] t [ A ]0 = kt t ½ = 0.693 k k = rate constant t = time t ½ = half-life GASES, LIQUIDS, AND SOLUTIONS PV = nRT moles A PA = Ptotal × XA, where XA = total moles Ptotal = PA + PB + PC + . . . n= m M K = °C + 273 D= KE per molecule = m V 1 mv 2 2 Molarity, M = moles of solute per liter of solution A = abc THERMOCHEMISTRY/ ELECTROCHEMISTRY q = mcD T DSD = Â SD products - Â SD reactants D HD = Â D HDf products - Â D HDf reactants D GD = Â D GfD products - Â D G Df reactants D GD = DHD - T D SD = - RT ln K = -n F E D I   q t P= V= T = n= m= M = D= KE = Ã = A= a= b= c = pressure volume temperature number of moles mass molar mass density kinetic energy velocity absorbance molar absorptivity path length concentration Gas constant, R = 8.314 J mol - 1 K - 1 = 0.08206 L atm mol- 1 K - 1 = 62.36 L torr mol- 1 K - 1 1 atm = 760 mm Hg = 760 torr STP = 0.00 DC and 1.000 atm q m c T SD = = = = heat mass specific heat capacity temperature = standard entropy HD = standard enthalpy GD = standard free energy n = number of moles E D = standard reduction potential I = current (amperes) q = charge (coulombs) t = t ime (seconds) Faraday’s constant, F = 96,485 coulombs per mole of electrons 1 joule 1volt = 1 coulomb