George feels very energetic and active on some days of the month and engages in gardening, washing laundry, and other menial jobs till early morning hours. on other days, he feels very depressed, inactive, and does not even get up from his bed. he is eventually diagnosed with bipolar disorder. his psychiatrist is most likely to prescribe to treat his condition.

8.29 two streams containing pyridine and acetic acid at 25°c are mixed and fed into a heat exchanger. due to the heat-of-mixing effect, it is desired to reduce the temperature after mixing to 25°c using a stream of chilled ethylene glycol as indicated in the diagram. calculate the mass flow rate of ethylene glycol needed. the heat capacity of ethylene glycol at these conditions is approximately 2.8 kj/(kg k), and the enthalpy change of mixing (δmixh) is given below.