Need help with this problem. Please help! The space shuttle uses the oxidation o

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Need help with this problem. Please help!

The space shuttle uses the oxidation of methyl hydrazine,N2H3CH3(l), for propulsion. The oxidation proceeds by the followingreaction: 5N2O4(g) + 4N2H3CH3(l) --> 12H2O(g) + 9N2(g) + 4CO2(g)The standard enthalpies of formation are: methyl hydrazine +54kJ/mol dinitrogen tetroxide +9.2 kJ/mol water (g) -242 kJ/molcarbon dioxide -394 kJ/mol Determine the amount of heat generatedby the shuttle,in kilojoules, if it is carrying 467.0 kg of methylhydrazine in its thruster. Assume that methyl hydrazine is thelimiting reactant. Enter your answer in scientific notation.

Thank you.

Explanation / Answer

               5N2O4(g)+ 4N2H3CH3(l) --> 12H2O(g) + 9N2(g) + 4CO2(g) Hrxn = Hf products - Hf reactents            =[ 12 (Hf (H2O)) + 9 ( Hf (N2)) + 4 (Hf (CO2)) ] - [ 5 ( Hf (N2O4)) + 4 ( Hf (N2H3CH3)) ]            =[ 12 (-242 kJ) + 9 (0) + 4 (-394 kJ) ] - [ 5 ( 9.2 kJ) + 4 (54kJ)]            =-4742 kJ 4 moles of methyl hydrazine gives this heat so 1 mole will give 4742 / 4 = 1185.5 kJ Moles of methyl hydrazine = Mass / molar mass                                         =467 * 1000 g / 46.07 g/mol                                        =10136.74 moles So heat given will be 10136.74 * 1185.5 =12017115.25                                                                   = 1.2 * 107 kJ                                                                   = 1.2 * 107 kJ

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