PF1010 HAM 2425 Tutorial 3 Slides PDF

Tutorial. Thermochemistry problems A. Given the enthalpies of formation (at 298 K) of fumaric acid and maleic acid are −807.6 and −784.4 kJ mol−1 respectively, determine Hrxn for the following process. maleic acid → fumaric acid (at 298 K) B. Glucose (C6H12O6) is metab...

Tutorial. Thermochemistry problems A. Given the enthalpies of formation (at 298 K) of fumaric acid and maleic acid are −807.6 and −784.4 kJ mol−1 respectively, determine Hrxn for the following process. maleic acid → fumaric acid (at 298 K) B. Glucose (C6H12O6) is metabolised in the presence of oxygen (O2) to give carbon dioxide (CO2) and water (H2O). (i) Write a balanced equation for the reaction of glucose and oxygen to give carbon dioxide and water (ii) Using the following data (305 K), calculate the enthalpy of the process. Hf⁰ C6H12O6 (s) = −1273.0 kJ mol−1 Hf⁰ O2 (g) = 0 kJ mol−1 (element) Hf⁰ H2O (l) = −285.8 kJ mol−1 Hf⁰ CO2 (g) = −393.5 kJ mol−1 Thermochemistry tutorial A. Given the enthalpies of formation (at 298 K) of fumaric acid and maleic acid are −807.6 and −784.4 kJ mol−1 respectively, determine Hrxn for the following process. maleic acid → fumaric acid (at 298 K) Thermochemistry tutorial answers A. Given the enthalpies of formation (at 298 K) of fumaric acid and maleic acid are −807.6 and −784.4 kJ mol−1 respectively, determine Hrxn for the following process. maleic acid → fumaric acid (at 298 K) ΔHrxn = (-807.6) – (-784.4) = - 23.3 kJ mol-1 Thermochemistry tutorial answers B. Glucose (C6H12O6) is metabolised in the presence of oxygen (O2) to give carbon dioxide (CO2) and water (H2O). (i) Write a balanced equation for the reaction of glucose and oxygen to give carbon dioxide and water (ii) Using the following data (305 K), calculate the enthalpy of the process. Hf⁰ C6H12O6 (s) = −1273.0 kJ mol−1 Hf⁰ O2 (g) = 0 kJ mol−1 (element) Hf⁰ H2O (l) = −285.8 kJ mol−1 Hf⁰ CO2 (g) = −393.5 kJ mol−1 First need balanced equation C6H12O6 + O2 → CO2 + H2O not balanced Thermochemistry tutorial answers B. Glucose (C6H12O6) is metabolised in the presence of oxygen (O2) to give carbon dioxide (CO2) and water (H2O). (i) Write a balanced equation for the reaction of glucose and oxygen to give carbon dioxide and water (ii) Using the following data (305 K), calculate the enthalpy of the process. Hf⁰ C6H12O6 (s) = −1273.0 kJ mol−1 Hf⁰ O2 (g) = 0 kJ mol−1 (element) Hf⁰ H2O (l) = −285.8 kJ mol−1 Hf⁰ CO2 (g) = −393.5 kJ mol−1 First need balanced equation C6H12O6 + O2 → CO2 + H2O not balanced C6H12O6 + 6 O2 → 6 CO2 + 6 H2O balanced Then use thermochemical data Hf⁰ C6H12O6 (s) = −1273.0 kJ mol−1 Hf⁰ O2 (g) = 0 kJ mol−1 (element) Hf⁰ H2O (l) = −285.8 kJ mol−1 Hf⁰ CO2 (g) = −393.5 kJ mol−1 C6H12O6 + 6 O2 → 6 CO2 + 6 H2O balanced ΔHrxn = [6(-393.5) + 6(-285.8)] – [(-1273.0) + 6(0)] = -2802.8 kmol-1