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Topic: Which reaction is most likely to occur? Halogens  (Read 4729 times)

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Offline THC

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Which reaction is most likely to occur? Halogens
« on: February 11, 2008, 03:32:24 AM »
Which reaction is most likely to occur?

2 F- + Cl2 -> F2 + 2 Cl-
or
2 Cl- + F2 -> Cl2 + 2 F-

Do I calculate the electrode potential E^0 for each reaction and compare? This is not an electrochemical reaction, so maybe not?

Offline 0000000

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Re: Which reaction is most likely to occur? Halogens
« Reply #1 on: February 11, 2008, 07:26:32 AM »
2 Cl- + F2 -> Cl2 + 2 F-

because the F have greater attraction to the electrons, but just to mention that the reaction it's not so simply.
My name is Bond, Covalent Bond

Offline THC

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Re: Which reaction is most likely to occur? Halogens
« Reply #2 on: February 11, 2008, 08:01:10 AM »
2 Cl- + F2 -> Cl2 + 2 F-

because the F have greater attraction to the electrons, but just to mention that the reaction it's not so simply.

I just wondered, what about calculating dG for both reactions and compare?

Offline 0000000

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Re: Which reaction is most likely to occur? Halogens
« Reply #3 on: February 11, 2008, 11:10:42 AM »
2 Cl- + F2 -> Cl2 + 2 F-

because the F have greater attraction to the electrons, but just to mention that the reaction it's not so simply.

I just wondered, what about calculating dG for both reactions and compare?

OK you can do that and you will get the same conclusion, but in cases like this think about the electronegative coefficients first
My name is Bond, Covalent Bond

Offline DevaDevil

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Re: Which reaction is most likely to occur? Halogens
« Reply #4 on: February 11, 2008, 04:20:43 PM »
F2(g) + 2e → 2F(aq)    E0 = +2.87 V
Cl2(g) + 2e → 2Cl(aq)    E0 = +1.36 V

reduction potential for fluor is highest, which means it will be the reduced species, so indeed:

2 Cl- + F2 -> Cl2 + 2 F- (E0, cell = 2.87 - 1.36 = 1.21 V ) is the preferred reaction.

Offline THC

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Re: Which reaction is most likely to occur? Halogens
« Reply #5 on: February 12, 2008, 12:30:41 AM »

OK you can do that and you will get the same conclusion, but in cases like this think about the electronegative coefficients first
Yes, that's probably what my teacher expected.

Thanks to both of you!

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