1. Mixtures containing solids dissolved in liquids can be separated and purified by evaporating the liquid and leaving behind a crystallized solid. One example of this is in desalination plants, where the water in saltwater is partially evaporated and then recondensed. The resulting streams are pure liquid water and saltwater with higher salt content. This process can be done more cost effectively with a series of small evaporators than with one very large evaporator. Consider the case where a saltwater stream with 3.0 wt% salt is fed to a series of 8 evaporators. The evaporators are designed so that each evaporates the same quantity of pure water. The saltier water is then fed to the next evaporator. The saltwater leaving the 8th evaporator contains 4.6 wt% salt.

A.1) Draw a flowchart showing the first, third, and eighth evaporator and label all relevant streams. Assume 10.0 kg of saltwater are fed to the process.

A.2) Calculate the mass of pure water recovered per mass of water in the process feed.

A.3) Calculate the weight percent of salt leaving the 5th evaporator. (Note: Thoughtful selection of control volume can save you a lot of algebra.)