Orsat analysis of the stack gas from the combustion of the gaseous mixture of ethane and methane shows 10.57%CO2, 3.79%O2 and the rest N2. The air enters at 46C and the barometer reads 760 mmHg. If the partial pressure of water in the stack gas is 135 mmHg, what is the relative humidity of the incoming air?

A. 42% B. 54% C. 70% D. 66%

Ans: A