N-hexane is burned with excess air. an analysis of the product gas yields the following dry-basis molar composition: 6.9% co2, 2.1% co, 0.265% c6h14 ( o2 and n2). the stack gas emerges at 760mm hg. calculate the percentage conversion of hexane, the percentage excess air fed to the burner, and the dew point of the stack gas, taking water to be the only condensable species.