A sample of D-ribose(C5H10O5) with mass 0. 727 g was weighed into a calor
A sample of D-ribose(C5H10O5) with mass 0. 727 g was weighed into a calorimeter and then ignited in presence of excess oxygen. The temperature rose by 0.910 K when the sample was combusted. In another separated experiment in the same calorimeter the combustion of 0. 825 g of benzoic acid,for which the ΔcUΘm= 3251 kJ·mol-1,gave a temperature rise of 1.940 K. Calculate the ΔrUΘmand ΔrHΘmof D-ribose combusted.