Pentaborane BH,(s) burns vigorously in O2 to give B2O3(s) and H2O(l). Calculate the heat given off, in KJ, for the combustion of 148.82 g of B5H9. AH[B2O3(s)]=-1,241.1 kJ/mol AH [BSH,(s)] 72.6 kJ/mol AH [H2O(1)]=-285.8 kJ/mol