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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: OnyX on May 03, 2015, 04:42:00 PM

Title: Why does F2 have a much lower boiling point than I2 ?
Post by: OnyX on May 03, 2015, 04:42:00 PM

Would I be correct in saying that, as F2 is smaller than I2 it has much fewer electrons which effects its ability for intermolecular bonding. Because of the lack of electrons, the dispersion forces such as induced dipoles (or van de waals forces) are much weaker, resulting in a lower boiling point.

Would that be sufficient for 2 marks ?

Title: Re: Why does F2 have a much lower boiling point than I2 ?
Post by: thetada on May 03, 2015, 06:22:29 PM

Depends on the exam board but for Ocr AS then yes, I'd give that 2 marks

Title: Re: Why does F2 have a much lower boiling point than I2 ?
Post by: vansh123 on May 16, 2015, 03:18:44 PM

 The boiling point of a liquid substance depends on the strength of the intermolecular forces. The stronger these interactions the more energy you need to provide to break them so that the molecules go into the gaseous phase. As Teroy mentioned in this case you have only London forces, that is induced dipole-induced dipole forces. Iodine is more polarizable because it is bigger, thus induced dipoles are more readily formed, which results in stronger intermolecular interactions and finally in higher boiling point.