Problem #$3(10$ points$)$

Compare the heats of combustion of n$-$octane, aluminum, and boron on molar, mass, and volume

bases: their respective densities are $0\mathrm{.}703\frac{g}{c}{m}^3,2\mathrm{.}70\frac{g}{c}{m}^3,$ and $2\mathrm{.}34\frac{g}{c}{m}^3.$ The complete

oxidation product of Al and B are respectively $A{l}_2{O}_3$ and $B_2{O}_3.$ These values indicate the

potential of boron as a high$-$energy$-$density fuel, provided that complete combustion can be

achieved.