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Complete the following writing assignment on another sheet of paper. This assign

ID: 509458 • Letter: C

Question

Complete the following writing assignment on another sheet of paper. This assignment will be due at the start of recitation on Monday. April 10th or Tuesday. April 11^th for 6 WA points; this will not be accepted late or through email. Be sure to show all of your work; be sure to dearly write your name and your recitation section number (failure to do so will cost you 3 WA points). Fructose, C_6H_12O_6 (s), is a sugar found in fruits and a source of energy for the body. The combustion of fructose takes place according to the following equation: C_6 H_12O_6 (s) + 6 O_2 (g) rightarrow 6 CO_2 (g) + 6 H_2 O(l) When 5.00 grams of fructose are burned in excess oxygen in a bomb calorimeter with a heat capacity of 29.7 kJ/K, the temperature of the calorimeter increases by 2.635 K. Calculate the standard enthalpy of combustion per gram and per mole of fructose. Assume that Delta H_rxn = Delta E_rxn.

Explanation / Answer

The rxn of interest is:

C6H12O6 (s) + 6 O2 (g) 6 CO2 (g) + 6 H2O (l)

5 g of fructose = 5/180.16 = 0.0277 moles of fructose

The heat given off by the combustion is:

q = = dE = -C * dT = - 29.7 (kj/K) * (2.635 K) = - 78.2595 KJ

This means that you give off 78.2595 KJ when 0.0277 moles are burned;
therefore, when 1 mole is burned you'll give off

q = 78.2595/0.0277 = -2825 KJ/mol

dH = dE + (d(P V))
      = dE + dn R T
Since the total numbers of moles of gases (6) before the reaction is the same as that after the reaction, dn = 0
   dH = dE
       = - 2825 KJ/mol