Question

Calculate the enthalpy of combustion. Write a balanced combustion reaction for the oxidation of your substance to CO2 and H2O. From the stoichiometry of this reaction and the amount of sample you used, find delta(PV) and thus calculate deltaH. Compare your value of deltaH with the literature value. deltaH = deltaU + delta(nRT) = delta U + RT(delta n). the combustion equation is C₁₂H₂₂O_11(s)+12O_2(g)arrow12CO_2(g)+11H₂O_(l) for sucrose. There are 0.1544g of sucrose combusted in a constant volume calorimeter. Please explain and show how to do this. Thank you!

Answer 1

C12H22O11(s) + 12O2(g) -------------> 12CO2(g) + 11H2O(l)

delta Hrxn = delta H of products - delta H of reactants

delta H rxn = [12*delta H of CO2 + 11*delta Hf of H2O ] - [ delta Hf of C12H22O11 + 12*delta Hf of O2]

delta Hrxn = -5639.808 KJ/mol

Moles of sucrose = mass /Molar mass = 0.1544 / 342 = 0.00045146

delta Hrxn = 0.00045146 *(-5639.808KJ/mol) = -2546 J

From formula:

deltaH = deltaU + delta(nRT)

But temperature not given , we need more information for applying this formula