A 2.3 g sample of C5H10O is burned completely in excess oxygen to yield CO2(g) and H2O(l) at 25 C, releasing 83.42 kJ of energy. What is the enthalpy of formation of C5H10O?

1 answer

What is the DHf for C5H10O?
5C + 5H2 + 1/2 O2 = C5H10O

The combustion reaction is what?
C5H10O + 7O2 ==> 5CO2 + 5H2O
DHf rxn = (5*DHf CO2 + 5*DHf H2O) - (DHf C5H10O)
Look up values for DHf for CO2 and H2O, plug into the equation above with DHf rxn and solve for DHf C5H10O