clc
// initialization of variables

// The reaction equation with theoritical air is 
// C8H18 + 12.5(O2+3.76N2)---> 8CO2 + 47N2 + 9H2O

// for 400% theoritical air reaction is

// C8H18 + 50(O2+3.76N2)---> 8CO2 + 188N2 + 9H2O + 37.5O2

// All the enthalpy of formation values are taken from Table B.5 with units in kJ/mol
hfCO2=-393520 // enthalpy of formation associated with CO2
hbarCO2=42769 //enthalpy associated with CO2 at 1000K from table E.4
hdotbarCO2=9364//enthalpy associated with CO2 at 298K from table E.4
hfH2O=-241820 // enthalpy of formation associated with gaseous H2O
hbarH2O=35882 //enthalpy associated with H20 at 1000K from table E.6
hdotbarH2O=9904//enthalpy associated with H20 at 298K from table E.6
hbarN2p=(30784+29476)/2 //enthalpy associated with N2 at 1000K from table E.2 by averaging enthalpy at 1020K and 980K 
hdotbarN2=8669//enthalpy associated with N2 at 298K from table E.2

hfC8H18=-249910 // enthalpy associated with octane taken from internet as not provided in textbook
hbarO2=31389 // enthalpy associated with O2 at 1000K table E.3
hdotbarO2=8682//enthalpy associated with O2 at 298K table E.3

Hp=8*(hfCO2+hbarCO2-hdotbarCO2)+9*(hfH2O+hbarH2O-hdotbarH2O)+37.5*(hbarO2-hdotbarO2)+188*(hbarN2p-hdotbarN2)// enthalpy of products

Hr=(hfC8H18)
// enthalpy of reactants

Q=Hp-Hr // using first law2

printf(" The heat transfer is %i kJ",Q)

//The answers are slightly different in textbook as they have approximated the values while in SCILAB results are precise