Formal charges
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Formal charges
I was informed that formal charges are a component of the Lewis structure, do I have to write the formal charges for each of the atoms in the molecule when writing a Lewis structure.
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Re: Formal charges
Unless specifically instructed to do so, I don't think you need to write the formal charge for each Lewis structure you write. When you are trying to determine which Lewis structure for the particular molecule is most stable and ideal, it may be useful to write the formal charges in order to compare different structures to determine the right one.
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Re: Formal charges
I asked about this in class, you do not need to write the formal charge of each atom in its lewis structure, but if you're checking for resonance you'll need to calculate it and see if there are any alternate structures.
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Re: Formal charges
formal charges can be used to help determine the most stable lewis structure, however you dont need to explicitly state them unless the questions says so
Re: Formal charges
I don't think you would have to write the formal charges for each atom, but it is certainly helpful to do so when determining which lewis structure is the most stable. A formal charge of 0 is the most stable.
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Re: Formal charges
No you don't need to write formal charges, but it'll help you determine whether or not there is a resonance of a more stable structure.
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Re: Formal charges
i don't think it's required unless specified. but i always do because i find it to be super helpful to figure out the most stable form of a molecule
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Re: Formal charges
I wouldn’t necessarily write them out unless he asks for it on an exam. If you are doing it to check though, you can always do a short cut way, the equation would be number of valence electrons - sticks & dots. So the number of electrons of one element, minus the sticks and dots drawn around it. Works every time.
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Re: Formal charges
It is not necessary but it is a good way to figure out if your lewis structure can be improved or not. I would do it just in case. If the question asks specifically for you to add the formal charges, then do so, but if not then it is your choice.
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Re: Formal charges
If we disregard the formal charges when drawing our lewis structure will it be wrong?
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Re: Formal charges
Roni Touboul wrote:If we disregard the formal charges when drawing our lewis structure will it be wrong?
It could possibly be wrong if there is a better lewis structure that will give the most atoms a formal charge of zero, or if an atom that is not as electronegative as another has a negative formal charge. It would be best to calculate the formal charges of each atom to see if you have made the best lewis structure, and if it can be improved, change the structure.
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Re: Formal charges
i dont think you have to write it but it should be used to create your structure and make sure you did it correctly and have no extra overall charges (whether positive or negative) in your structure
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Re: Formal charges
My TA said that points might be marked off if the lewis structure was not accompanied by formal charges on the midterm. I recommend writing them just in case.
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Re: Formal charges
It might be better to calculate the formal charge of each atom so that you can choose the most stable structure.
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Re: Formal charges
If they are asking for the most stable Lewis structure then the formal charges are necessary but just to be safe I would put them.
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Re: Formal charges
usually you do not have to write the formal charge of each atom for points unless instructed to do so, but it will help you find the correct lewis structure by demonstrating which structure will have the lowest energy.
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