The standard heat of reaction for the combustion of liquid n-nonane to form CO2 and liquid water at 25°C and 1 atm is ΔH˚г = —6124 kJ/mol.

(a) Briefly explain what that means. Your explanation may take the form “When ______ (specify quantities of reactant species and their physical states) react to form (quantities of product species and their physical state), the change in enthalpy is _________”

(b) Is the reaction exothermic or endothermic at 25°C? Would you have to heat or cool the reactor to keep the temperature constant? What would the temperature do if the reactor ran adiabatically? What can you infer about the energy required to break the molecular bonds of the reactants and that released when the product bonds form?

(c) If 25.0 molls of liquid nonane is consumed and the reactants and products are all at 25°C, estimate the required rate of heat input or output (state which) in kilowatts, assuming that Q = ΔH for the process. What have you also assumed about the reactor pressure in your calculation? (You don’t have to assume that it equals 1 atm.)

(d) The standard heat of combustion of n-nonane vapor is ΔH˚г = —6171 kJ/mol. What is the physical significance of the 47 kJ/mol difference between this heat of combustion and the one given previously?

(e) The value of ΔH˚г given in part (d) applies to n-nonane vapor at 25°C and 1 atm, and yet the normal boiling point of n-nonane is 150.6°C. Can n-nonane exist as a vapor at 25°C and a total pressure of 1 atm? Explain your answer.