Melting Points

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Nada AbouHaiba 1I
Posts: 77
Joined: Fri Sep 28, 2018 12:28 am
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Melting Points

Postby Nada AbouHaiba 1I » Thu Nov 29, 2018 12:02 am

Can someone explain why CHI4 has a higher melting point than CHF4. Thanks!

Patrick Cai 1L
Posts: 93
Joined: Fri Sep 28, 2018 12:25 am

Re: Melting Points

Postby Patrick Cai 1L » Thu Nov 29, 2018 12:09 am

The first molecule possesses iodine atoms, which are substantially larger than the fluorine atoms found in the second molecule. With a larger atomic number, iodine has more electrons and a larger electron cloud. Iodine, therefore, has a larger polarizability value than fluorine and forces a group of the CHI3 to exhibit stronger London dispersion forces compared to CHF3. This stronger London dispersion force is then responsible for higher energy requirements when attempting to melt solid made of CHI3 compared to the energy required for melting solid CHF3.

Nada AbouHaiba 1I
Posts: 77
Joined: Fri Sep 28, 2018 12:28 am
Been upvoted: 1 time

Re: Melting Points

Postby Nada AbouHaiba 1I » Thu Nov 29, 2018 11:12 am

Patrick Cai 3L wrote:The first molecule possesses iodine atoms, which are substantially larger than the fluorine atoms found in the second molecule. With a larger atomic number, iodine has more electrons and a larger electron cloud. Iodine, therefore, has a larger polarizability value than fluorine and forces a group of the CHI3 to exhibit stronger London dispersion forces compared to CHF3. This stronger London dispersion force is then responsible for higher energy requirements when attempting to melt solid made of CHI3 compared to the energy required for melting solid CHF3.


Thank you! That makes more sense now


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