100 moles of a fuel containing methane and butane is burned with 25% excess air in a furnace producing stack gas at 300 degrees C and 105 kPa. Determine the amount of 100 psi saturated steam that can be produced from water fed in at 10 degrees C, if
a) The stack gas does not contain methane, butane or CO,
b) The dew point of the stack gas is 58 degrees C, and
c) The air enters at 20 degrees C as dry air.