Chemistry Unit 10 Answers

2- CHOH(5) +702(g)→6 CO2(g) + 3 H2O(l) When a 2.000-gram sample of pure phenol, C₂H₂OH(s), is completely burned according to the equation above, 64.98 kilojoules of heat is released. Use the information in the table below to answer the questions that follow. Standard Heat of Absolute Entropy, Formation, ΔΗ at 25°C (kJ/mol) S°, at 25°C (J/mol-K) Substance C(graphite) 0.00 5.69 CO2(g) -393.5 213.6 H2(g) 0.00 130.6 H₂O (1) -285.85 69.91 02(8) 0.00 205.0 CH3OH(5) ? 144.0 (a) Calculate the molar heat of combustion of phenol in kilojoules per mole at 25°C. -3058 KJ (b) Calculate the standard heat of formation, AH, of phenol in kilojoules per mole at 25°C. - 161KJ (c) Calculate the value of the standard free-energy change, AG, for the combustion of phenol at 25°C. -3032KJ (d) If the volume of the combustion container is 10.0 liters, calculate the final pressure in the container when the temperature is changed to 110.°C. (Assume no oxygen remains unreacted and that all products are gaseous.) 601 atm Free Response Thermo 2- 2 Fe(s) + O2(g) → Fe2O3(s)∆H = -824 kJ mol-1 Iron reacts with oxygen to produce iron(III) oxide as represented above. A 75.0 g sample of Fe(s) is mixed with 11.5 L of O2(g) at 2.66 atm and 298 K. (a) Calculate the number of moles of each of the following before the reaction occurs. (i) Fe(s) 1.34 (ii) O2(g) 1.25 (b) Identify the limiting reactant when the mixture is heated to produce Fe2O3. Support your answer with calculations. Fe I Calculate the number of moles of Fe2O3 produced when the reaction proceeds to completion.. 671 (d) The standard free energy of formation, AG of Fe2O3 is-740. kJ mol-1 at 298 K. (i) Calculate the standard entropy of formation AS/ of Fe2O3 at 298 K. Include units with your answer. 0.282 kJ/mol.k (ii) Which is more responsible for the spontaneity of the formation reaction at 298K, the standard enthalpy or the standard entropy? much larger The reaction represented below also produces iron(III) oxide. The value of AH for the reaction is -280 kJ per mol. 2 FeO(s) + O2(g) → Fe2O3(s) (e) Calculate the standard enthalpy of formation, AHf of FeO(s). 272 KJ/40/