Butane (c4h10) burns completely with 110% of theoretical air entering at 74°f, 1 atm, 50% relative humidity. the dry air component can be modeled as 21% o2 and 79% no on a molar basis. the combustion products leave at 1 atm. determine the mole fraction of water in the products, in lbmol(water)/bmol(products). there is a ±5% tolerance.

Athin walled concentric tube exchanger is used to cool engine oil from 160°c to 60°c with water that is available at 25°c acting as a coolant. the oil and water flow rates are each at 2 kg/s, and the diameter of the inner tube is 0.5 m and the corresponding value of the overall heat transfer coefficient is 250 w/m2. oc. how long must the heat exchanger be to accomplish the desired cooling? cpwater=4.187 kj/kg-candcpengine el=2.035 kj/kg·°c, oil . 120]