One kilogram butane (C4H10) of is burned with 25 kg of air which is at 35 degree Celcius and 100 kPa. Assuming the combustion is complete and the pressure of the products is 100 kPa, determine the mole number (in kmol) of air per kmol of fuel for stoichiometric combustion, (b) the mole number (in kmol) of air per kmol of fuel for actual combustion, (c) the percentage of theoretical air used, and (d) the dew-point temperature of the products.