A stream of 5.00 wt% oleic acid in cottonseed oil enters an extraction unit at a rate of 100.0 kg/h. The unit operates as an equilibrium stage (the streams leaving the unit are in equilibrium) at 85C. At this temperature, propane and cottonseed oil are essentially immiscible, and the distribution coefficient (oleic acid mass fraction in propane/oleic acid mass fraction in cottonseed oil) is 0.15. (a) Calculate the rate at which liquid propane must be fed to the unit to extract 90% of the oleic acid. (b) Estimate the minimum operating pressure of the extraction unit (i.e., the pressure required to keep the propane liquid at 85C). (c) High-pressure operation is costly and introduces potential safety hazards. Suggest two possible reasons for using propane as the solvent when other less volatile hydrocarbons are equally good solvents for oleic acid.

Psych Stats Powerpoint 6 ● we can identify important sections of the normal distribution using z- scores ● because we know what percent of scores falls in each part of the distribution, we can define the normal distribution in terms of proportions ○ these percentages/proportions apply to any normal distribution, regardless of the values for the mean and SD ● 68-95-99.7% rule ● if you know the z-score, you can find the proportion above or below that score using the unit normal table Unit Normal Table ● lists proportions of the normal distribution for a range of possible z- score values ● imagine you draw a line at a particular z-score ○ t