Understanding Melting Points for the Periodic Table

[komal12]

hi

i am having a hard understanding melting points from my textbook. can someone please explain to me how they work and how you can determine melting points in the periodic table?

 

[komal12]

Can anyone help me with this:

element solubility in water Melting

NaF 0.042 988
NaCl 0.357 801
NaBr 1.16 755
NaI 1.84 651

Explain the decreasing melting point from NaF to NaI?

I think it has to do with covalent and ionic bonds...because NaF is ionic it has a higher because its harder to pull the electrons apart and NaI more covalent so it has a lower melting point...am i close please help..!

 

[chaoseverlasting]

Yeah, youre on the right track.

 

[chemisttree]

Can anyone help me with this:

element solubility in water Melting

NaF 0.042 988
NaCl 0.357 801
NaBr 1.16 755
NaI 1.84 651

Explain the decreasing melting point from NaF to NaI?

I think it has to do with covalent and ionic bonds...because NaF is ionic it has a higher because its harder to pull the electrons apart and NaI more covalent so it has a lower melting point...am i close please help..!

No, you are not on the right track...

Bond energy tracks with ionic/covalent character but melting point is more related to the nature of the lattice that makes up the material. Neat, tightly packed lattices with equal size anions and cations will have a higher melting point than one with ions of different sizes. This is more important to melting point than the bond strength.

http://www.Newton.dep.anl.gov/askasci/chem00/chem00800.htm