Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

6.(15 pts) The space shuttle orbiter utilized the oxidation of methyl hydrazine

ID: 909995 • Letter: 6

Question

6.(15 pts) The space shuttle orbiter utilized the oxidation of methyl hydrazine by . dinitrogentetroxide for propulsion. The balanced reaction is 5N2O4(l) + 4N2H3CH3(l) = 12H2O(g) + 9N(g) + 4CO2(g) Calculate DeltaH^0 for the reaction. In addition to tables in your book you will need the following data: N2H3CH3 (l) deltaHf^0 = 54.0 kJ/mole N2O4(l) deltaHf^degree = -20.0 kJ/mole Consider two Styrofoam coffee cups. If cup #1 contains 128O mL of water at 88.0 degree C and cup #2 contains 59.6 mL of water at 18.5 degreeC, what is the final temperature, in C, when the contents of cup #1 are poured into cup #2? Ignore the heat capacity of the cup. Assume that the density of water is 1.00 g/mL.

Explanation / Answer

6) delta H = 4(CO2) + 12(H2O) - 5(N2O4)-4(N2H3CH3)

= 12(-241.8) + 4(-110.5) - 5(-20)-4(54)

= -3459.6 KJ/mole

7) Applying energy conservation

mSdT = mSdT

= 128 (88-T) = 59.6 (T-18.5)

=88-T = 0.46T -8.61

= 96.61 = 1.46T

= 66.17 = T