The course will provide an overview of the fundamentals of the molten salt chemistry that an engineer should understand in order to work on design of molten salt systems. The focus is primarily on molten halide salts (fluorides, chlorides). The topics discussed include chemistry, thermodynamics, and salt properties. They also include transport of chemical species in a flowing loop. They also include several applications to corrosion in molten salt, and specifically corrosion in flowing loop with a thermal gradient. Phase diagrams will be introduced from the point of view of how a phase diagram is constructed, and what kind of information can be derived from it that would be useful to a designer of a molten salt system.