Find AG for the following reaction, at 25°C, using AH and S f NH4Cl(s) NH3(g) + HCl(g) kJ Substance or Ion HCl(g) HCl(aq) NH3(g) NH3(aq) NH4Cl(s) and S values. Standard Thermodynamic Values at 298 K AH (kJ/mol) ΔΗ f -92.3 -167.46 -45.9 -80.83 -314.4 S (J/mol K) 186.79 55.06 193 110 94.6

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Use the data given here to calculate the values of AGan at 25 °C for the Compound AG; (kJ/mol) reaction described by the equation A +387.7 В +596.8 A + B =C +402.0 AGAN kJ

Calculate the standard free-energy change AG® and the equilibrium constant K, for the following reaction at 25°C. CO(9) + 2H2 (9) CH; OH(9) AG¡ (kJ/mol) Substance CO(g) H2 (9) CHOН (9) -137.2 -162.0 AG" = kJ Ky

Use the given data at 298 K to calculate AG°for the reaction CH4(g) + 2H2S(g) → CS2(g) + 4H2(g) Substance AHof (kJ/mol) S°(J/K·mol) O -50 kJ O 67 kJ O 184 kJ CH4(9) H2S(g) CS2(g) H2(g) -75 186 2.27 x 104 kJ -21 206 90 151 0 131

One of the reactions that destroys ozone in the upper atmosphere is NO(g) + O3(g) ⇒ NO2 (g) + O2(g) Substance and State AGf (kJ/mol) NO(g) 87 NO₂(g) 52 0₂ (9) 0 03 (9) 163 a Calculate ΔG° (at 298 K) for this reaction. AG = -198 kJ b Calculate K (at 298 K) for this reaction. K =

2. For the following reaction at 25°C, AG° is -118.4 kJ. At what pressure of O2 gas does AG = 0 at 25°C? 2 KCIO3 (s) + 2 KCI (s) + 3 O2 (g)

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Incomplete combustion of hydrocarbons produces the toxic gas Carbon monoxide can be eliminated by the reaction shown: CO + H2O ⇌ CO2 + H2 ΔH° = −41.0 kJ/mol and ΔS° = −42.3 J cal/(mol·K) at 25°C and 1 atm. What is ΔG° for this reaction? (What is ΔG if the gases have the following partial pressures: P(CO) = 1.3 atm, P(H2O) = 0.8 atm, P(CO2) = 2.0 atm, and P(H2) = 1.3 atm? What is ΔG if the temperature is increased to 150°C assuming no change in pressure?