Register to reply

Thermal stability vs melting point

by sgstudent
Tags: melting, point, stability, thermal
Share this thread:
sgstudent
#1
Feb15-12, 06:28 AM
P: 645
An ionic compound is more thermally stable when the metal cation is more reactive. So its harder to decompose. But then what's the difference between melting and decomposition?

Also, when an compound is harder to decompose, does it mean its melting point is higher? Because even though Na2O should be more thermally stable, it has a lower melting point than MgO.

Thanks so much for the help!
Phys.Org News Partner Chemistry news on Phys.org
Chemists eye improved thin films with metal substitution
Essential oils may provide good source of food preservation
Artificial skin flexes when it comes into contact with a solvent vapour
Borek
#2
Feb15-12, 07:21 AM
Admin
Borek's Avatar
P: 23,363
Quote Quote by sgstudent View Post
But then what's the difference between melting and decomposition?
This one you should be able to answer by yourself. Cool the sample down - what will be the result in both cases?

As far as I know there is no direct connection between thermal stability and melting point. Or at least there is no universal connection - it may exist for specific types/families of compounds.
sgstudent
#3
Feb15-12, 09:06 AM
P: 645
Oh ok. So when I say that Na2O is more thermal stable than MgO, I cannot use that to determine its melting point? Oh and is it that melting is a physics change while decomposition is a chemical change?

Thanks Borek!

Dr_Morbius
#4
Feb16-12, 04:53 PM
P: 155
Thermal stability vs melting point

Quote Quote by sgstudent View Post
Oh ok. So when I say that Na2O is more thermal stable than MgO, I cannot use that to determine its melting point? Oh and is it that melting is a physics change while decomposition is a chemical change?
Exactly. There is no connection between meting point and decomposition point. When a substance decomposes it is no longer the same substance it was before it decomposed. It is now a different substance.


Register to reply

Related Discussions
Boiling Point before Melting Point? Chemistry 13
Impurities on melting point and boiling point of water Chemistry 9
Melting point Biology, Chemistry & Other Homework 3
Melting point Chemistry 1
Melting point of 40% Sn and 60% Pb Chemistry 11