Find H for the combustion of ethanol C6H6O to carbon dioxide

Find ?H for the combustion of ethanol C6H6O to carbon dioxide and liquid water from the following data. The heat capacity of the bomb calorimeter is 34.65 Kj/K and the combustion of 1.749 g of ethanol raises the temperature of the calorimeter from 294.04 K to 295.54 K<?xml:namespace prefix = o ns = \"urn:schemas-microsoft-com:office:office\" />

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Solution

There is no mention how much water is warmed up in the bomb calorimeter, so presumably it is included in the heat capacity figure [and you haven\'t left out part of the question]

Temp rise = 1.15K
so energy change = 34.65 x 1.15 = 39.8475 kJ

Molar mass of methanol CH3OH = 12 + 3 + 16 + 1 = 32g

so 1.754g methanol gives 39.8475 kJ
so 1 mole gives 39.8475/1.754 x 32 = 727.97834 kJ
so delta H = - 727.97834 kJ per mole