Amixture of iso-propanol (more volatile, i-proh) and n-propanol has an approximately constant relative volatility of 1.8. 100 kmol/h of a saturated liquid feed containing 40 mol% i-proh is available. the distillate is to contain 90% i-proh, and the bottoms product 10% i-proh. a. if the reflux ratio is 4, how many ideal stages are required for this separation? do stage-by-stage calculations by hand or the mccabe-thiele method. b. what is the minimum reflux ratio possible? c. what is the minimum number of stages needed for this separation? d. compare the results for parts (a) to (c) to what is obtained using the fug method.

Oxygen is contained in a piston-cylinder system initially at a temperature of 40 °c and a pressure of 150 kpa. the piston is 1 m in diameter and initially 20 cm above the base of the cylinder. heat is added at constant pressure until the piston has moved 30 cm. a)-what is the mass of gas contained in the piston, in kg? b)-what is the final temperature of the system, in k? c)-using the table of properties of oxygen as an ideal gas, calculate the heat added to the system per unit mass, in kj/kg. d)-repeat this calculation assuming that the specific heat as a function of temperature is linear over this range of temperatures (i.e., assuming that the change in temperature is "small"). e)-repeat this calculation without this assumption (i.e., direct integration of empirical relation) f)- discuss the variations in your results across the methods (note: all methods will give close to the same answer, if calculated correctly). g)-using any of the methods that you conclude to be accurate, calculate the change in the specific internal energy of the system, in kj/kg.