posted by Kathleen .
What is the importance of a freezing point depression graph and why and what things change when different solutes and solvents are added?
Do you mean by "freezing point depression graph" taking readings of the temperature at timed intervals and plotting them? If so, the graph provides a permanent record as well as allowing one to study the details at will. It also provides information about the possibility of the ability to form a supercooled liquid. Different solvents freeze at different temperatures. Different solutes perform the same unless they are ionized. The depression depends only on the number of dissolved particles, all other things being equal.