A gas contains 80.0 wt% propane, 15.0 wt% -butane, and the balance water. Calculate the composition of this gas on both a wet and a dry basis and the ratio (mol H O/mol dry gas). If 100 kg/h of this fuel is to be burned with 30% excess air, what is the required air feed rate (kmol/h)? How would the answer change if the combustion were only 75% complete?