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Topic: Melting Points  (Read 4752 times)

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jena

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Melting Points
« on: February 02, 2005, 05:22:10 PM »
Hi

I don't really understand the principle behind melting points? Why is necessary to know the melting points of an item?

Thank You  :)

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Offline Mitch

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Re:Melting Points
« Reply #1 on: February 02, 2005, 05:45:23 PM »
They are used as a measure of purity.
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Offline Donaldson Tan

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Re:Melting Points
« Reply #2 on: February 02, 2005, 07:10:03 PM »
if melting/freezing a substance is among the steps you take in a chemical process, you gotta know the melting point in order to make an estimate for the required energy input for the entire process. it's not only an economical issue but also knowing if your equipment can tolerate the heat output and pressure changes throughout the process.
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dexangeles

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Re:Melting Points
« Reply #3 on: February 03, 2005, 12:26:35 AM »
example1: you need to record the melting point of a salt substance and you decide to use a melt-temp....if you don't know the melting point is probably over 400 degrees, and you decide to use the melt-temp at #2 (slow heat) setting, you'll be there all day  ;)

example2: helps isolate a desired substance (just like distillation - gota know the Bp and keep it there to isolate the desired compound)

example3: it helps provide for finding out what an unkown is (besides ftir, nmr, gc, etc...)  Imagine if we don't have a CRC book for reference of melting points.  Organic is hard enough :'(
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