Thermochemistry
Liquidized hydrazine, N2H4, and liquid 1, 1-dimethylhydrazine, N2H2(CH3)2, both react spontaneously with O2 and can be used as rocket fuel.
Reaction A: N2H4(l) + O2(g) = N2(g) + 2H20(l)
Reaction B: N2H2(CH3)2(l) + 4O2(g) = N2(g) + 4H2O(l) + 2CO2(g)
a. Use the given information to calculate deltaHrxn for reactions A and B. Please show your work.
| Compound | Standard enthalpy of formation deltaHformation |
| N2H4(l) | 50.6kJ.mol |
| N2H2(CH3)2(l) | 48.9kJ.mol |
| O2(g) | 0kJ/mol |
| H2O(l) | -285.8kJ/mol |
| CO2(g) | -393.5kJ/mol |
| N2(g) | 0kJ/mol |
b. If you have 5.00kg of each liquid rocket fuel, which will provide more energy? Show the calculation of energy for each compound.
