How are melting and freezing points different?

Answer 1

the freezing point is 0 degrees celsius and the melting point is is above 0 degrees celsius

Answer 2

It's a fairly subtle distinction, and I'm not absolutely positive that this is formally correct, but my experience has been that melting point is used for substances that melt at a precise temperature, and melting temperature is used for substances (such as polymers, where there may be a mixture of molecular weights) where melting isn't as sharply defined.

Answer 3

not all compounds melt at one specific temperature. some can melt over a range of temperatures. With regards to foods this is called the plasticity of a food. For example chocolate and butter do not simple melt at one temperature, instead they melt over a range.

Answer 4

Any temperature difference; they are synonyms.

But traditionally:

- freezing is used to name the change from a liquid to a solid phase

- melting is used to name the change from a solid to a liquid phase

Answer 5

Melting points are made on solids by slowly heating them and measuring the temperature at the same time. Once completely melted its return to a solid (freezing) can be followed by watching it cool although this is not usually done.

Freezing points are generally made on liquids by following the temperature as they are cooled, usually with a surrounding liquid at a temperature below the expected freezing point. Determining the freezing point can be a problem if the liquid tends to cool below its freezing point - called supercooling- if it is not stirred or mixed in some way. When a supercooled liquid suddenly freezes the temperature of it rises sharply to the freezing point.

The temperature stays at the melting or freezing point while there is still some liquid and solid of the substance present together. Thus boiling pure water in an open container stays at 100 degrees centigrade until it has all boiled away. It does not get hotter the longer it is boiled. The temperature taken up is disposed off as steam. If the container is closed as in a steam engine then the steam can superheat. There are laws of physics that define these processes, e.g. water boiling on top of a mountain at a lower temperature due to the lower air pressure etc.

Most pure substances have well defined melting or freezing points (listed in books of such data) but contaminants can make them different (for example, a contaminant would usually lower a melting point) so for chemists this is an important way of checking the purity of a substance.

Answer 6

Melting: change of phase, from solid to liquid

Melting point: the temperature that this change phase happens

Answer 7

Freezing point is the point where a liquid turns into a solid. Melting point is the point where a solid turns into a liquid.

Answer 8

Melting point is the point where a solid melts into a liquid. Freezing point is where a liquid OR solid freezes.