Equations Flashcards
State the equation for the first law of thermodynamics and annotate.
∆U = q + w
∆U: change in internal energy
q: transfer of heat
w: work
State the equations for ∆H (2).
∆H = ∆H(products) - ∆H(reactants)
∆H = ∆U + p∆V
State the equation used for calculating standard reaction enthalpy.
∆rH = Zn∆fH - Zn∆fH
Z: sum of
n: number of moles of each reactants/product
State the equations for ∆S (4) and when they are used.
∆S = Sf - Sin - used when calculating entropy ∆S = qrev/T - used when heat is added reversibly ∆S = ∆H/T - used for a phase transition ∆S = Cvln(T2/T1) - calculating heat flow from the molar heat capacity
State the Boltzmann formula.
S = kB ln W
kB: Boltzmann constant
W: number of ways of arranging molecules and their energies.
State the equations for Gibbs free energy (2).
∆G = ∆H - T∆S
∆rGo = -RTlnK
State the Clausius-Clapeyron equation.
ln (p2/p1) = -(∆vapH)/R (1/T2 - 1/T1)
State the reaction equation for the Haber process.
N2(g) + 3H2(g) –> 2NH3(g)
State the temperature dependence van Hoff equation.
ln (K2/K1) = -(∆rH)/R (1/T2 - 1/T1)
Calorimeter constant.
∆U = -Ccal∆T
Reversible isothermal expansion.
w = nRTln(Vf/Vin)
Kirchoff’s Law.
∆rH[T2] = ∆rH[T1] + ∆Cp(T2-T1)
where:
∆Cp = ZnCp - ZnCp
Z: sum of for products and reactants
