1. A distillation column is separating methane, ethane, propane, and butane. We pick methane and propane as the keys. This means that ethane is a distributed non-key or "sandwich" component. a. Show the approximate composition profiles (i.e. mole fraction vs stage in the column) for each of the four components. Label each curve. Do not use real values, just think about how they should behave in the column from top to bottom and around the feed stage. b. Explain in detail the reasoning used to obtain the profile for ethane. Hint: Look what happens to DNK or "sandwich" components and where they tend to concentrate.