Two humid gas streams are combined in a heated mixing chamber. The first stream contains 23.5 mole% ethane and 76.5% ethylene on a dry basis and enters the chamber at 25°C and 105kPa at a rate of 125L/min. The second stream is humid air, which enters at 75°C and 115 kPa at a rate of 355 L/min. The product stream emerges at 65°C and 1.00 atm. A hygrometer is used to measure the water contents of the two feed streams and the combined product stream. The calibration curve for the hygrometer is a straight line on a semi log plot of y (mole fraction of water) versus R (hygrometer reading), which passes through the points (y = 10^–4, R = 5) and (y = 0.2, R = 90). The following readings are recorded. Hydrocarbon Feed Stream: R = 86.0 Air Feed Stream: R = 12.8

(a) Derive an expression for y(R).

(b) Calculate the volumetric flow rate of the product stream and the molar composition of the product gas on a dry basis.

(c) Calculate the partial pressure of water in the product gas and the hygrometer reading for this stream.