The fuel used in spacecrafts must contain as much energy per gram of material as possible. Based on this consideration only, which of the following fuels is best suited to be a spacecraft fuel?
(i) dimethylhydrazine, (CH3)2NNH2 Hcombustion = -1694 kJ/mol
(ii) methanol, CH3OH Hcombustion = -726 kJ/mol
(iii) ethanol, C2H5OH Hcombustion = -1371 kJ/mol
(iv) octane, C8H18 Hcombustion = -5500 kJ/mol
(v) ethylene glycol, C2H6O2 Hcombustion = -1190 kJ/mol