Part B Consider the reaction C12H22O11(s)+12O2(g)12CO2(g)+11H2O(l) in which 10.0

Question

Part B Consider the reaction C12H22O11(s)+12O2(g)12CO2(g)+11H2O(l) in which 10.0 g of sucrose, C12H22O11, was burned in a bomb calorimeter with a heat capacity of 7.50 kJ/C. The temperature increase inside the calorimeter was found to be 22.0 C. Calculate the change in internal energy, E, for this reaction per mole of sucrose. Express the change in internal energy in kilojoules per mole to three significant figures. E = 565 kJ/mol SubmitHintsMy AnswersGive UpReview Part Incorrect; Try Again; 4 attempts remaining

Explanation / Answer

The heat produced in a bomb calorimeter when combusting a given amount of known substance is the internal energy of the substance combusted per the number of moles of the substance that was burned.

Here 10.0 g of sucrose is (10.0 g of sucrose) / (342.3 g/mol) = 0.02921 moles of sucrose

You are given that the heat capacity of the calorimeter is 7.50 kJ/ deg C. This means that the temperature of calorimeter increases 1 deg C when 7.50 kJ of heat is absorbed by the calorimeter from the combustion process. Since the temperature increase was 22.0 deg C when combusting the 0.02921 moles of sucrose, then the combustion process must have given off (22.0 deg C)(7.50 kJ/deg C) = 165.0 kJ..

Therefore, the change in internal energy per mole of sucrose combusted would be = (165.0 kJ) / (0.02921 moles of sucrose combusted) = 5649 kJ/mol of sucrose combusted

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