On a warm, muggy day, a fuel mixture of propane and butane is burned with air. The composition of the air is 77 mol% N2, 20.5 mol% O2, and the remainder H2O. The propane and butane are completely combusted. On a dry basis, the analysis of the product gas shows 3.60% O2 and 11.51 mol% CO2, with the remainder N2. a. What is the mole% propane in the fuel mixture? b. What is the %excess air used to combust the fuel? For this problem, you can use atomic species balances, extents of reaction for the two reactions, or a combination of the two.