Formal charge and dot structures | Chemical bonds | Chemistry | Khan Academy

Definition of formal charge, and how minimization of formal charge can help choose the more stable dot structure.
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[@abdulharrison4380]

It's been 4 years since a lot of you guys watched this video to learn a thing or two. Meaning, you guys have since graduated and most likely moved into the cooperate world at the moment. I hope you have a blessed life with your families. We're right behind as well. And thank you khan academy for being a blessing to soo many of us. Thank you!

[@FATASSSOVIET]

You taught this much better than my Chem professor and He has a PhD.....

[@raphaelmarcelo4411]

i have to agree with you :")

[@GershanBarnardNorman]

most professors are in actual fact hired as researchers, meaning their core function at the university is to do research, not to teach. my point is, Being good teachers is not their priority; their priority is to produce quality research papers, because universities aren't ranked according to the marks of students. They are ranked according to the most amount of quality research published.

[@whatblank4157]

that explains a lot. i only go to lectures just get to my clicker points.

[@sylveriate]

A PhD in chemistry, not a PhD in education. Experts don't always make good teachers.

[@marvelhasiholan5495]

maybe you don't pay attention in class.

[@joshpark2739]

I have had 3 people try to explain to me what formal charge is and you did it in 8 mins. It isn't hard at all! Thank you!

[@ratatat12356]

whats the dot structure for a james bond?

[@retrodude8586]

😂😂😂

[@abelkahsai9599]

If you have question,use their website,link is in the description,there you'll see a list of there videos, click on the one you want, if it's not already highlighted ,then scroll down to the bottom of the page,it might sometimes take a bit to show up.there they have a conversation section, where there is a whole lot of answers to questions related to that specific video. There you could also signin and ask a question for yourselves. It's great really.As far as I know khan academy don't answer questions on KZbin's comment sections,they have integrated KZbin to their website,I think they use it as a way of getting revenue.There is MORE info about who they are(a non profit organization) and what they offer(free education) in the description.

[@00eun2]

After watching this video. I feel that dot structure and finding charge is not that difficult

[@LunaticBiker11]

cool

[@hamedhosseini4938]

Thanks, very usefull

[@theroadtoari3861]

thank you guys so much. I couldn't understand it when my Professor lectured today.

[@austinlindquist7584]

Quick question, how do you know that the Hydrogens are attached to the oxygens rather than the sulfur?

[@masterchief1372]

Something to with it being an acid I think

[@josephsherby]

You might already know this by now because it’s been two years, but we know the hydrogen’s are attached to the oxygen because they will dissociate in water, so they must easily break off. It’s how all acids are, I believe.

[@kuanlinpaihan]

thumbs up if khan is ur lord and savior

[@LunaticBiker11]

u are my lord and savior

[@seeksolace2059]

Lord and savior.........nah

[@bryced2846]

only Jesus is

[@atiksh2004]

@@bryced2846 no

[@alexcoreablecoreable]

is it right to say VE in bonded atom?i believe since the electrons are shared, the electrons shared between one bond plus the lone pair(s) should be all considered VE? isn't better to describe it as formal charge=VE in free atom - lone pair - 1/2shared electron, it may look more complicated tho.

[@tunneltrance]

is there a difference tho? for memorizing purposed I think this video's explanation of it is easier. Is there any situation where this video's method would not work?

[@raymondkanabr9770]

Very nice video. I think what would make it perfect is if the sub titles did not cover some of the work. Other than that; the video was very helpful.

[@superiorchocolate6886]

U literally saved me thank-you so much😃 but in our books the formula is no.valence electron -no of unshared electrons -1/2the no of shared electrons . like if we use your formula we will get same ans in every case?

[@shaghayegh4888]

the final answer will be same as this solution. so, dont care about difference

[@calebisaac4919]

life saver, thank you so much :)

[@bettyagajyelleh8043]

thank you! so helpful

[@tedstudt8550]

thanks so much!!!

[@dalilarobledodebasabe191]

Awesome!

[@ChickpeaBlues]

We always did coordinate covalent bonds for sulfuric acid.

[@erickamau8144]

well put

[@charlesrosenthal3511]

So are we trying to get the formal charge of every atom to 0?

[@avijitdey992]

Charles Rosenthal Because compounds which exists in our nature have a formal charge of zero. Molecules with a formal charge more than zero is generally not available in nature

[@albadadkola3301]

thanks 😊

[@108mtsan]

Haha you are Japanese. :)

[@albadadkola3301]

Oh no ! 😂 I'm not japanese , I'm just a Naruto fan

[@occupytosavetheworld]

Concise

[@alissajeanfreau7741]

Why does it matter to move around the structure when the overall formal charge was already 0 because the Sulfur was +2 and the two Oxygen's were -1. 2 -1 -1 = 0. Please explain

[@jiminchiii5341]

Uhm...can I ask how to know if it is a posive or negative??

[@rafidayad4143]

thanks

[@Gooners0710]

anyone please tell me the significance of formal charge...why we calculate it?#i know how to calculate# so please don't tell me how to calculate it....just tell me why we calculate it?

[@seanhartwick2243]

Fireblaze 1998 The reason to calculate formal charge is to see which structure you would actually find in the real world. Real world structures are as close to a formal charge of zero as possible.

[@coolmanmomo12345]

my techer said the formal charge is the number of valance electrons for the molecule minus the number of bonds with the molecules minus the number of unpaired electrons I have checked using this method and got same results. but might there be an exception or something?

[@abelkahsai9599]

The same,its just a different way of thinking about it.

[@pravintiwari8777]

but bond pair means electron involved in making bond then have you included lone pairs electron too in the formula explain/.

[@zenosaa8655]

Oxygen has 6 VE. While bond formation the Oxygen and other atom ,say Sulphur has to lend an e- to form a bond but u have drawn 7 e- in the terminal oxygen atom . How?

[@abidaadhil9777]

99 duriarion -1.-9

[@SRS-wu6sz]

Hello these concepts are now in class 11😅

[@squigglxs00]

I may have not caught this while watching the video, but towards the end, why is he trying to get the formal charge closest to 0?

[@avijitdey992]

Naomi Castro Because compounds which exists in our nature have a formal charge of zero. Molecules with a formal charge more than zero is generally not available in nature.

[@allyanaalbor3422]

Sulur had more than 8 electrons and some were lacking. This gave me confusion because you didn't obey the octet rule

[@daybreak2127]

Sulfur doesn't have to obey the octet rule, it is on the 3rd row of the periodic table.

[@megansaul-escobar9619]

How is it that Sulfur can form 6 bonds?

[@LunaticBiker11]

nah fooooool

[@jordyvandenbempt2409]

how does the top oxygen form a bond with S as if it has 7 electrons?

[@LunaticBiker11]

i love u

[@angelovaldez7612]

someone pls, why need to minimize formal charge of central atom?

[@baha17222]

Angelo Valdez the formal charge is related to the energy level of the structure. Lone pairs have higher energy level than bonded pairs so the oxygens formed a double bond. The effect of this change is minimizing the formal charge. So when drawing a structure the one with the least formal charge is probably the most accurate one because it has the least energy and is the most stable

[@beautifulpakpk1594]

nitrogen provide one bond that two electrons are from nitrogen.

[@adonis1168]

such a simple thing dwelled on for what it seemed like hours. just get to the point

[@FRAUSTIN867]

How does sulfur form 6 bonds?

[@shawncarlson1880]

+austin straub Octet rule exception

[@santoryu8940]

+Shawn Carlson whats the octet rule exception?

[@shawncarlson1880]

Dog that was 16 weeks ago I forgot haha

[@venkatmourya5117]

It can have a expanded octet

[@LunaticBiker11]

yeeeeeeeee

[@tendertv5769]

nice

[@ezpzwins7613]

Whats a formal charge

[@abelkahsai9599]

kzbin.info/www/bejne/gaeYqmaqbs-mn5Y

[@sakama40]

N has 5 electrons, where is the last one (NH4)

[@shawncarlson1880]

+joe xtz It was NH4+. the + meaning it loses an electron. therefore it was one less.

[@sabrinamartino849]

How is nitrogen in group 5 ? i thought it was 15?

[@albadadkola3301]

its atomic no is 15 so arranging umm its k shell has 2 e L shell has 5 e and its outermost/valence M shell has 5 e , the group no. represents the no of valence e therefore N is in grp 5

[@sabrinamartino849]

ohhh okay thank you

[@noatreiman]

its atomic number is definitely not 15

[@rishijagtap1177]

it's atomic number is 7 and and it is in group 15 which is also known as V-A(5). And by the way you're right . Naruchi Uzumaki has explained it. But he/she is wrong about atomic number

[@albadadkola3301]

RiSHi JagTaP Yeah yeah u're correct sry I messed up with the atomic no

[@thefryingpan951]

wait i dont get it, oxygen only has 6 valence electrons, Sulfur only has 6 valence electrons, why do you give Oxygen 7, and then sulfur 4?

[@abelkahsai9599]

Watch their video on formal charges and resonance Website link:- www.khanacademy.org/science/chemistry/chemical-bonds/copy-of-dot-structures/v/formal-charge?modal=1 KZbin link:- kzbin.info/www/bejne/gaeYqmaqbs-mn5Y The 7 electrons for oxygen or the 4 electrons for sulfur are actually not the valency electron, ever thing is explained in the videos.

[@abidaadhil9777]

9

[@hopesy12u4]

Am I the only one who thinks that the "octet" of electrons around oxygen in H2SO4 are a bit off?

[@repentandbelieveinjesus33]

@Kevin Nguyen ya i was getting really confused by it

[@abelkahsai9599]

The octer rule could be off, for elements in and above the third period, since sulphur is in the 3rd period,it is acceptable if it has more than 8 electrons

[@abidaadhil9777]

1

[@tyepete2236]

slow down!!!

[@LunaticBiker11]

skrrrt

[@abidaadhil9777]

@it 77

[@MG-hm8rk]

Donde esta mi hijo sal

[@santoshsaroj9685]

Sabhi ko english nahi aati hai sir

[@jackperry6605]

this is wrong, the oxygens have to be more electronegative then the sulfer.

[@sonnajensen4824]

Why? The least electronegative atom always, or at least almost always, belongs in the center of the molecular structure. Sulfer is less electronegative than oxygen.