#4 Find ΔGo for the following reaction, at 25°C, using ΔHof and So values. NH4Cl(s)→NH3(g) + HCl(g) =____kJ Standard Thermodynamic Values at 298 K Substance or Ion ΔHof(kJ/mol) So(J/mol K) HCl(g) −92.3 186.79 HCl(aq) −167.46 55.06 NH3(g) −45.9 193 NH3(aq) −80.83 110 NH4Cl(s) −314.4 94.6

The relevant thermodynamic data, under standard conditions, for the reaction H2(g) + ½O2(g) → H2O(g) are summarised below: Entity: H2O(g) ∆hf ° kJ mol−1: −241.81 ∆gf ° kJ mol−1: −228.59 (a) Compute the equilibrium constant K of this reaction at T = 298 K. (b) Compute the corresponding K at 500 K. To simplify your calculations for this temperature, it is suggested you make the appropriate simplifying assumption. State the assumption you have made.

Standard thermodynamic data at 298K: ΔGof (kJ/mol) CO(g) = -137.2 Cl2 (g) = 0 COCl2 (g) = -204.6

What is ΔrS for a reaction that has ΔrH = -64.8 kJ mol-1 and ΔrG = 84.7 KJ mol-1 at 19.9 °C? Express your answer in J mol-1 K-1