Researchers at Purdue University have exploited the reactivity of a reaction to develop a novel type of rocket fuel consisting of aluminum nanoparticles dispersed in H2O(s). They nicknamed this propellant “ALICE” (get it? Al-ice) and noted that in addition to being environmentally friendly, ALICE could be produced on any extraterrestrial body that contains water. The recent discovery of water on Mars could draw new attention to this intriguing fuel. (International Journal of Aerospace Engineering, 2012)
One can speculate that the reaction that causes ALICE to act as a propellant is:
2Al (s) + 3H2O(s) → Al2O3(s) + 3H2(g)
where the hydrogen gas is subsequently burned.
A. Given the molar enthalpies for the following reactions,
2Al(s) + 3/2 O2 (g) → Al2O3 (s) ΔH° = -1669.8 kJ/mol
H2 (g) + 1/2 O2 (g) → H2O (l) ΔH° = -285.8 kJ/mol
H2O (s) → H2O (l) ΔH° = 6.01 kJ/mol
determine the ΔH° for the ALICE reaction
2Al (s) + 3H2O (s) → Al2O3 (s) + 3H2 (g)
Is the ΔH° you calculated consistent with Al-ice serving as a fuel? ________________
Give one reason to support your answer.