Question

(a) A muscle can be thought of as a fuel cell, producing work from the metabolism of glucose (C6H1206): C6H1206 (glucose) +202(9) + 2H2O(l) + CO2(g). (0.1) Here g and I refer to the gaseous and liquid states, respectively. Using data given in the table, please determine the values of AH and AG for this reaction for one mole of glucose, assuming that the reaction takes place at room temperature and atmospheric pressure. Substance CH 20. (glucose) 0 (9) H200 CO2(9) A H (kJ/mol AG (kJ/mol S J/K mol) -1273 -910 212 205.14 -285.83 -237.13 69.91 -393.51 -394.36 213.74 TABLE I: The values given in the table are for substances at room temperature (298 K) and pressure (1 bar). (b) Assuming ideal operation, what is the maximum amount of work that a muscle can perform for each mole of glucose consumed? (c) How much heat is absorbed or expelled by the chemicals during the metabolism of a mole of glucose? Please state the direction of heat flow. (d) Using the concept of entropy, please explain why the heat flows in the direction it does.

Answer 1

[H2O +60,(9) — 6C0,19) + 6H20 (e) 6 286, + 6 +4860 6 4440 - Achame = 6% (-393-51) +6(-285.83)-0- (-1273) AHE -2803.04 ksIf mole B = 6 Bf Go + 649-6AG. - Aug & 6*(-394-36) + 6(-237.13) – o-(-910) DG = – 2878.94 kJ/moli The maximum amount of work that a muscle can perform for each mole of gluwse =- AG =-(-2878.94 k) = 2878.94 kJ @ ( @ The amount of heat expelled = 2803.04 kJ AS = 6X213.74 +6X 69.91 – 6X205.14-212 = 259.06 J/i. if heat flow is away from the system (le heat is expelled), it would contribute towards decrease in free energy and more spontaneous the reaction becomes. heat expelled would contribute towards the increase in entropy of surroundings. and spontanity of reaction would be more.