Wilhoit Equation: Ideal-gas Heat Capacity Cpo and derived properties

Cpo / R = a0 + (a1/T 2) × exp(-a2 /T ) + a3 ×y2 + {a4 - a5 /(T - a7)2}×y 8
where R is the gas constant. If T is greater than a7, then y = (T - a7)/(T + a6). If T is less than or = a7, then y = 0.

Enthalpy Function:
(H(T) naught - H(0) naught) / (R × T) = a_0 + a_1 × exp(-a_2 / T) / (a_2 × T) + I / T + h(T) / T, with
h(T) = (a_6 + a_7) × [(2 × a_3 + 8 × a_4) × ln(1-y) + {a_3 × (1 + 1/(1 - y)) + a_4 × (7 + 1/(1 - y))} × y + a_4 × (3 × y^2 + 5 × y^3 / 3 + y^4 + 3 × y^5 / 5 + y^6 / 3)+{a_4 - a_5 / (a_6 + a_7)^2} × y^7 / 7]

Entropy (at standard pressure po = 100 kPa):
S(T) naught / R = J + a_0 × ln(T) + a_1 / a_2 × (1 + a_2 / T) × exp(-a_2 / T) + s(T), with
s(t) = {a_3 + ((a_4 × a_7^2 - a_5) / (a_6^2))} × (a_7 / a_6)^2 × ln(z) + (a_3 + a_4) × ln((T + a_6)/(a_6 + a_7)) + summation from i=1 to 7 of [{((a_4 × a_7^2 - a_5)/(a_6^2)) × (-a_7 / a_6)^(6-i) - a_4} × y^i / i] - {((a_3 × (a_6 + a_7)) / (a_6))) + ((a_5 × y^6) / (7 × a_7 × (a_6 + a_7)))} × y ,
where z=T / (T + a_6) × (a_7 + a_6) / a_7 and x(a_2) = exp(-a_2 / T)

Equation Parameters: (Output details)

See Thermodynamics of Organic Compounds in the Gas State (Volumes I and II) by M. Frenkel, G. J. Kabo, K. N. Marsh, G. N. Roganov, and R. C. Wilhoit. Published by the Thermodynamics Research Center (TRC), College Station: TX. 1994. ISBN 1-883400-04-X