Heat of fusion

Definition:
The heat of fusion is the heat needed to melt 1 gram of a solid at constant Temperature. The quantity of heat that is absorbed during fusion or melting is released during solidification or freezing.

Formula: H=mHf
Units: Joules per gram and/or calories per gram


Notes/Explanations:
Heat of fusion can be observed if you measure the temperature of waters as it freezes. Whenever people try to caculate the heat of something they could use the formula for heat of fusion. For example when scientist caculate the calories that are in a food item they would take the original weight of the item and heat the item after the item is heated they would recored the mass of the item and would get and overall andser in calories per gram.
The temperature at which heat of fusion occurs is called the melting point. The heat of fusion of water is 79.72 calories per gram or 334 joules per gram.

Everyday Example:


(Solid turning into liquid)

Example: Draw and label the following information in the graph below. Freezing point,solid,liquid, and melting point


Whiteboard video

http://www.physchem.co.za/Heat/Latent.htm (Link to other useful websites)