Radicals

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Sarai Ventura 1L
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Radicals

Postby Sarai Ventura 1L » Sun May 13, 2018 9:01 pm

On Friday during lecture the TA's talked about radicals, can someone please explain when we are able to use them or the concept of radicals.
Thank You.

Kara Justeson 1B
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Re: Radicals

Postby Kara Justeson 1B » Sun May 13, 2018 9:13 pm

the concept of a radical is that it is any atom that has an unpaired valence electron, but I'm not sure how we use them.

Liliana Rosales 1E
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Re: Radicals

Postby Liliana Rosales 1E » Sun May 13, 2018 9:23 pm

Basically a Lewis structure with one lone pair would be considered a radical. They tend to be really reactive because electrons like to form bonds instead of being a lone pair. You would say your compound is radical when your Lewis structure ended up having one lone electron.

Chem_Mod
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Re: Radicals

Postby Chem_Mod » Sun May 13, 2018 10:03 pm

Radicals have an unpaired electron, not 1 lone pair.

Sarah Brecher 1I
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Re: Radicals

Postby Sarah Brecher 1I » Wed May 16, 2018 11:52 am

If you are asked to do a Lewis structure of a molecule with a radical, one of the biggest things to consider is the formal charge. Even though you have an odd number of electrons, it is still possible for some molecules to do a Lewis structure without any formal charges and you should make sure to write your Lewis structure off of that.

alexagreco1A
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Re: Radicals

Postby alexagreco1A » Sun May 20, 2018 6:07 pm

I understand the concept of a radical, but when drawing Lewis structures, how do we decide which element has the unpaired electron?

Ashley Martinez 1G
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Re: Radicals

Postby Ashley Martinez 1G » Sun May 20, 2018 9:38 pm

As far as radical placement goes, I believe we can look at electronegativity. According to the textbook, an atom of the element with the higher electronegativity has a stronger pulling power on electrons and tends to pull them away from the atom of the element with lower electronegativity. Also, I remember at the end of the T.A-led Friday lecture they mentioned we can also use formal charge to decide where to place the radical. I'm not sure if it's better to use electronegativity or formal charge to determine radical placement though.

Chiara Berruto 1K
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Re: Radicals

Postby Chiara Berruto 1K » Sun May 20, 2018 9:41 pm

Free radicals are highly reactive molecules with an unpaired electron, they attack stable molecules in an attempt to "steal" an electron and are neutralized by antioxidants which donate an electron

Sonia Aronson 1B
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Re: Radicals

Postby Sonia Aronson 1B » Mon May 21, 2018 11:10 pm

A radical is a molecule or atom with an unpaired electron that makes the molecule or atom highly reactive. We use radicals often in cases of resonance because they can stabilize atoms who share the electron.

BriannaParrington-1B
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Re: Radicals

Postby BriannaParrington-1B » Tue May 22, 2018 4:49 pm

Just to add to this discussion, from my knowledge, if you were to count the number of valence electrons in a compound such as NO, nitrogen has 5 valence electrons and oxygen has 6 valence electrons. In total, the entire compound's total valence electron is 11. Therefore, there must be an electron that is unpaired since electrons usually come in pairs. So there will be 5 pairs of electrons and 1 electron that is unpaired, making 11 electrons. So, there is a radical. I am not sure if the NO compound even exists unless it's some sort of ion, but on a problem these are the steps you should follow to find if there is or is not a radical.

John Miller-1I
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Re: Radicals

Postby John Miller-1I » Sun Jun 03, 2018 9:53 pm

The easiest way to determine a radical is just to count the number of electrons and if it is an odd number the structure is radical

Molly Oakes 1A
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Re: Radicals

Postby Molly Oakes 1A » Sun Jun 03, 2018 9:56 pm

alexagreco1A wrote:I understand the concept of a radical, but when drawing Lewis structures, how do we decide which element has the unpaired electron?
I believe you place the radical where it makes sense to due to formal charge.

OrAmar-1L
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Re: Radicals

Postby OrAmar-1L » Mon Jun 04, 2018 8:49 pm

Does an atom in the molecule being a radical have anything to do with the formal charge? Im looking for ways to tell that there will be a radical.

Raquel Floyd 1K
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Re: Radicals

Postby Raquel Floyd 1K » Wed Jun 06, 2018 5:56 pm

The way to tell that something is a radical is that it will only have a lone electron (as stated above). How it affects formal charge is now you have an odd number of electrons. Say you have nitrogen (which wants 5 electrons) and it is bonded to some other element, has a lone pair, and a single electron (note: this is some hypothetical, I am not sure if there is such a molecule that exists to make this situation possible. It is only to demonstrate the effect radicals have on formal charge). The formal charge of the nitrogen in this situation would then be +1. You get this by subtracting the number of electrons nitrogen wants (5), by the number of electrons involved. You have two electrons from the lone pair, 2(1/2) from the bond, and one electron from the lone electron. This gives you 5-(2+1+1) = +1. If nitrogen in this situation was not a radical, and just had the one bond and lone pair, the formal charge would work out to be 5-(1+2) = +2.


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