A 1.2 g sample of C-5 H-10 O is burned completely in excess oxygen to yield CO2(g) and H2O(l) at 25 C, releasing 43.52 kJ of energy. What is the enthalpy of formation of C-5 H-10 O?

Answer 1

delta H = DH.
DHrxn = (n*DHf products) - (n*DHf reactants).
DHrxn = 43,520 J.
n = the appropriate coefficients in the balanced equation for each compound you look up for DHf.
DHf = look up these values in your text or notes.
Post your work if you get stuck.