2006-09-26 13:02:39 · 5 answers · asked by marvin_motley 1 in Science & Mathematics ➔ Chemistry
Some substances undergo a phase transition very rapidly, some have a region in which they change, and some take pretty much forever. Since you're measuring something you don't know (presumably), you'll never know which it's going to be until too late and then you have to start over. If you've never used melting point measuring equipment, I can tell you that it's pretty easy to do!
Likewise there are other considerations: What if the heat transfer causes a chemical reaction in your substance? What if one part is hotter than another? What if impurities start precipitating out (or dissolving in!)? You have to keep a close eye on things to eliminate all possible sources of error.
2006-09-26 13:08:29 · answer #1 · answered by Doctor Why 7 · 0⤊ 1⤋
It depends on the sample, but to determine the melting point, you want a very precise temperature. You want to determine when it first starts to melt. Also, some samples will blow up if heated too quickly.
2006-09-26 20:05:40 · answer #2 · answered by happygirl 6 · 0⤊ 1⤋
if you apply heat too rapidly the material will melt rapidly too and before you can read the melting point the temperature has changed already and thus you get the wrong melting point...
best answer?
2006-09-26 20:10:47 · answer #3 · answered by teroy 4 · 0⤊ 1⤋
Because the heat needs to transfer all of the way through a material, rather than scorching the surface immediately.
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2006-09-26 20:05:17 · answer #4 · answered by Anonymous · 0⤊ 1⤋
So you can tell what temp it started melting at.
2006-09-26 20:04:36 · answer #5 · answered by Anonymous · 0⤊ 1⤋