Melting Point

Moderators: Chem_Mod, Chem_Admin

905596651
Posts: 73
Joined: Wed Sep 30, 2020 10:01 pm

Melting Point

Postby 905596651 » Sun Nov 22, 2020 8:54 pm

How do you tell which element has a higher melting point?

Gina Spagarino 3G
Posts: 62
Joined: Wed Sep 30, 2020 9:48 pm
Been upvoted: 1 time

Re: Melting Point

Postby Gina Spagarino 3G » Sun Nov 22, 2020 8:56 pm

The element or compound with stronger intermolecular forces (so more polarizable) has a higher melting point because then it takes more energy to overcome those IMF.

Melanie Lin 3E
Posts: 60
Joined: Wed Sep 30, 2020 9:38 pm

Re: Melting Point

Postby Melanie Lin 3E » Sun Nov 22, 2020 8:59 pm

Adding onto what Gina said, you can use the list of IMF's that Lavelle discussed in his lectures to see which molecules have stronger interactions depending the type of interaction.

Alison Perkins 2B
Posts: 63
Joined: Wed Sep 30, 2020 9:57 pm
Been upvoted: 1 time

Re: Melting Point

Postby Alison Perkins 2B » Sun Nov 22, 2020 9:01 pm

Melting points increase as the intermolecular strength of the atom increases. The more forces acting upon the nucleus to hold the atom together, the more energy required to break these.

Simrah_Ahmed3F
Posts: 63
Joined: Wed Sep 30, 2020 9:49 pm

Re: Melting Point

Postby Simrah_Ahmed3F » Sun Nov 22, 2020 9:02 pm

For molecules, those with stronger intermolecular forces have a higher melting point. Ionicly bonded crystals will have very high melting points, then hydrogen bonded molecules, then dipole-dipole, then weak London Disperson forces.

Algernon Jackson 2l
Posts: 52
Joined: Mon Jan 06, 2020 7:27 am

Re: Melting Point

Postby Algernon Jackson 2l » Sun Nov 22, 2020 9:06 pm

As the elements intermolecular forces increase, the melting point also increases.

Anthony_Sandoval_1D
Posts: 66
Joined: Wed Feb 19, 2020 12:15 am

Re: Melting Point

Postby Anthony_Sandoval_1D » Sun Nov 22, 2020 9:28 pm

A stronger intermolecular force leads to a higher melting point.

Nathaly Cruz 2D
Posts: 55
Joined: Wed Sep 30, 2020 10:06 pm

Re: Melting Point

Postby Nathaly Cruz 2D » Sun Nov 22, 2020 9:34 pm

The stronger IMF = higher melting point because you require more energy to break the bonds apart.

Danielle DIS2L
Posts: 61
Joined: Wed Sep 30, 2020 9:38 pm

Re: Melting Point

Postby Danielle DIS2L » Sun Nov 22, 2020 10:04 pm

An element has a higher melting point when the intermolecular force is strong. For instance, Iodine would have a higher melting point than Fluorine because Iodine has a bigger atom and is polarizable(more easily distortable cloud of electrons), thus, making the intermolecular force strong. I hope this helps :)

reyvalui_3g
Posts: 60
Joined: Wed Sep 30, 2020 9:52 pm

Re: Melting Point

Postby reyvalui_3g » Mon Nov 23, 2020 2:41 am

Whichever molecule has the highest IMF, because then it takes more energy (heat) to break the bonds between atoms.

TrishaP_3E
Posts: 50
Joined: Wed Sep 30, 2020 9:58 pm

Re: Melting Point

Postby TrishaP_3E » Mon Nov 23, 2020 8:25 am

This goes back to the difference in type of change, melting point is a phase change, which means that it concerns Intermolecular forces.

Gabriel Nitro 1E
Posts: 65
Joined: Wed Sep 30, 2020 9:32 pm
Been upvoted: 1 time

Re: Melting Point

Postby Gabriel Nitro 1E » Mon Nov 23, 2020 9:12 am

Hi,

Before we can deduce which element has a higher melting point, we need to understand what determines the melting point.

As the melting point is the temperature at which a substance transitions from a solid into a liquid, you can think of the temperature as an amount of energy (i.e. higher temperatures = higher melting points = higher amounts of energy needed). Now, when we melt something that energy is invested as you could say into disrupting those intermolecular forces holding the elements together.

Now, for the elements we will mostly concern ourselves with London Dispersion Forces (i.e. the weakest intermolecular force). When comparing elements, we tend to look at number of electrons and the overall size of the element as it determines its polarizability, and in turn the strength of the London Dispersion Forces.

Thus, the stronger the intermolecular attraction, the more energy required, and in turn a higher melting point.

Hope this helps! :)

jasonfarrales3D
Posts: 62
Joined: Wed Sep 30, 2020 9:55 pm

Re: Melting Point

Postby jasonfarrales3D » Mon Nov 23, 2020 2:52 pm

Looking at melting point, the higher the intermolecular force, the higher the melting point. With that being said, molecules with ion-ion bonds would usually have one of the highest melting point (as they are the strongest intermolecular force), while molecules with London dispersion forces usually have one of the lowest melting point (as they are one of the weakest intermolecular forces).


Return to “Bond Lengths & Energies”

Who is online

Users browsing this forum: No registered users and 1 guest