(Solved): Compounds of boron and hydrogen are remarkable for their unusual bonding and also for their reactiv ...

Compounds of boron and hydrogen are remarkable for their unusual bonding and also for their reactivity. With the more reactive halogens, for example, diborane \( \left(\mathrm{B}_{2} \mathrm{H}_{6}\right) \) forms trihalides even at low temperatures: \( \mathrm{B}_{2} \mathrm{H}_{6}(\mathrm{~g})+6 \mathrm{Cl}_{2}(\mathrm{~g}) \rightarrow 2 \mathrm{BCl}_{3}(\mathrm{~g})+6 \mathrm{HCl}(\mathrm{g}) \) \[ \Delta H_{\mathrm{rxn}}=-755.4 \mathrm{~kJ} \] How much heat is released when \( 1.642 \mathrm{~kg} \) of diborane reacts? (Give your answer in scientific notation.)