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3F.5 part c)

Posted: Wed Nov 20, 2019 5:06 pm
by LReedy_3I
In part C of question 3F.5, why exactly are the London forces in CHI3 stronger than those in CHF3? Is it because of the size of the atoms or the polarizability?

Re: 3F.5 part c)

Posted: Wed Nov 20, 2019 5:07 pm
by Brian_Ho_2B
Yes, the difference in the relative strengths of their LDF is due to their differences in polarizability. Because iodine is larger and has more electrons, it's more polarizable than chlorine, which is why the LDF in the compound with iodine is stronger and thus has a higher boiling point.

Re: 3F.5 part c)

Posted: Wed Nov 20, 2019 5:08 pm
by Cooper Baddley 1F
Both size means more electrons which means more polarizability which then leads to stronger London forces