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The standard enthalpy for selected organic compounds is given in this problem. For each, compute the gross and net heats of combustion. (a) Propane (C3H8);103.8kJ/mol (b) n-Butane (C4H10);124.7kJ/mol (c) Isobutane (C4H10);131.6kJ/mol (d) Ethanol (l), (C2H5OH);277.6kJ/mol (e) Methanol (l),(CH3OH);238.6kJ/mol 4. Problem 2.20, modified. Find the theoretical oxygen demand of the following: a. 200mg/L acetic acid, CH3COOH b. 30mg/L ethanol, C2H5OH c. 50mg/L glucose, C6H12O6 d. 100mg/L cyclopentane, C5H10