Question

Why do we need to know freezing point and melting point

Answer 1

http://www.quora.com/Why-do-we-need-to-know-the-melting-and-the-freezing-points-of-a-substance

Answer 2

Thank you very much bUT I need something more clearly

Answer 3

if you provide more information about what you are doing, a more suited answer can be posed

Answer 4

Thank you very much bUT I need something more clearly

Answer 5

you need to know the melting point and freezing point of a substance because then you can tell whether or not that substance undergoes a phase change in a reaction. You need to know whether or not theres a phase change because then you can find the specific heat of such phase change. you use this in the equation q=ms∆t where q is the system (or substance), m is the mass in grams, s is the specifics heat, and ∆t is the change in temperature.