Ionic compounds: most ionic vs highest melting point?

[FutureDDS_11]

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Hello everyone, so I have a quick question about this concept and I want to make sure that how my understanding is correct.
I have ran into two questions that kind of overlap
One where it asked which ionic compound has the most ionic compound (or something of that sort)
- So the most ionic compound is the one with the greatest difference in electronegativity (which make sense because the metal is more willing to give up its e- while the nonmetal is more willing to accept that e-)

However I ran into a second question which kind of confused me because it doesn't have the same concept as the first one
It asked about which Ionic compound has the highest melting point.
I assumed that the most ionic compound is also the one that has the highest melting point, which turned out to be wrong. My understanding now that the ionic compound with the highest melting point is the one with the greatest difference in charge, and size also plays a role (the smaller, the stronger the interaction b/c - and + closer together)

Is my understanding of the difference correct? So the most ionic compound does not play a factor in determining the one with highest melting point?

I know I tend to try to over confuse myself, but it kind of helps me solidify the concept in my studying.
Thanks in advance!

 

[Alpha Centauri]

Most ionic is the greatest difference in electronegativities I believe? The highest melting point would be the molecule with the largest charge difference shared 2 atoms, but take into consideration the size also. MgCl > melting point than that of NaCl

 

[FutureDDS_11]

Most ionic is the greatest difference in electronegativities I believe? The highest melting point would be the molecule with the largest charge difference shared 2 atoms, but take into consideration the size also. MgCl > melting point than that of NaCl

Thanks a lot, how is your pre-test day going? My exam is not until two weeks and just the thought of it terrifies me haha. Best of luck to you!

 

[Alpha Centauri]

Thanks a lot, how is your pre-test day going? My exam is not until two weeks and just the thought of it terrifies me haha. Best of luck to you!

Thanks! It's ok so far. Woke up at 8 because my sleep schedule is screwed up and won't let me sleep. Woke up and picked some snacks up from publix for tomorrow. Visited my Grandpa's grave and said a quick prayer to him (This sounds depressing but it isn't I felt really good after that). Now I am home I just did 15 questions each of cube counting, Hole punching, and TFE on the BC generators. Gonna review some of my review questions and call it a day. Maybe get some lunch with a few friends, go swimming to get some sun, etc. Then of course watching the Bachelorette later 😉

 

[FutureDDS_11]

Thanks! It's ok so far. Woke up at 8 because my sleep schedule is screwed up and won't let me sleep. Woke up and picked some snacks up from publix for tomorrow. Visited my Grandpa's grave and said a quick prayer to him (This sounds depressing but it isn't I felt really good after that). Now I am home I just did 15 questions each of cube counting, Hole punching, and TFE on the BC generators. Gonna review some of my review questions and call it a day. Maybe get some lunch with a few friends, go swimming to get some sun, etc. Then of course watching the Bachelorette later 😉

Sounds like a plan! Best of luck and don't be nervous, play your favorite song on your way to the testing center and then destroy that exam!

 

[Alpha Centauri]

Sounds like a plan! Best of luck and don't be nervous, play your favorite song on your way to the testing center and then destroy that exam!

For sure man thank you! Optimism is the key right now

 

[Charles_Darwin]

According to coulomb's law, melting point increases with increasing charge and decreasing size

 

[Don Kim]

Yea I don't think they expect you to compare electronegativities of all of the ionic compounds when they ask you that. More charge = more attraction. MgCl2 > NaCl as rich123321 said. Or even MgO. The two plus charge of Mg2+ of one MgO will also be attracted to the O2- of another MgO compound. I guess thats a simpler way of thinking about it. And if the charges are the same, then yeah, size of atoms should determine it. For example, BaO will probably have a lower melting point than MgO because its bigger, and would thus have a longer bond length. (shorter bond length = stronger bond = higher MP)