The heat capacity at constant pressure of hydrogen cyanide is given by the expression Cp[J/(mol'C)] = 35.3 + 0.0291T(C) (a) Write an expression for the heat capacity at constant volume for HCN, assuming ideal gas behavior. (b) Calculate LiH(1/mol) for the constant-pressure process HCN(v. 25C, 0.80 atm) -,> HCN(v. 100C, 0.80 atm) (c) Calculate LiO(1/mol) for the constant-volume process HCN(v. 25C, 50 m3 /kmol) -> HCN(v, 100C, 50 m3 /kmol) (d) If the process of part (b) were carried out in such a way that the initial and final pressures were each 0.80 atm but the pressure varied during the heating, the value of LiH would still be what you calculated assuming a constant pressure. Why is this so?
Organic Chemistry Equilibrium constant eA + fB sC + tD K eq[C] [D] / [A] [B] f Thermodynamics Y Z Thermodynamics: how much of ‘Z’ is formed Kinetics: How fast ‘Z’ is formed ∆G⁰ =RTln K eq logK eq pka (conjugate acid) pka (acid) ∆G⁰ = ∆H⁰ – T ∆S⁰ Bond dissociation Energy (BDE) = BDE (bonds broken) – BDE (bonds formed) HH + CH – C3 CH CH 2 CH – C3 2 H H Rate = frequency of collision X fraction of proper orientation X fraction with sufficient (How fast) (location) (energy)
