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4:54 AM
@YUSUFHASAN Thank you for the information.
@M.A.R. Thank you for the information.
 
 
2 hours later…
6:46 AM
Sir i am reading the notes of my sir where he describe ,how to find a limiting reagent in a chemical reaction ,is there any trick or something to find it fast
 
 
2 hours later…
8:27 AM
@Intellex Thank you for the Thank you
. . . for the Thank you for the Thank you for the Thank you . . .
@yuvrajsingh Hi, the only real trick is you do the process so many times that it almost becomes an instinct. Or muscle memory, if the brain had muscles. It also helps if you familiarize yourself with the numbers and how divisible they are. For example, in my shitty education, I had to memorize that molar gas volume in STP is 22.4 liters, and then I memorized that 224 is 16 x 14. Or KClO3's molar mass is 122.5 g/mol which is 35 times 35 times 0.1.
 
9:16 AM
@M.A.R. Welcome (for the thank you)$1^{\infty}$
MathJax doesn't work here?
@yuvrajsingh Just divide the given moles by the respective stoichiometric coefficients and look for the least value. The one which has least is the limiting reagent!
@yuvrajsingh, Are you preparing for JEE?
 
@M.A.R. I am facing a problem while solving limiting reagent
I have question wg
Like this
 
@Intellex see Main Chatroom Etiquette Guidelines for info on MathJax
@M.A.R. Everywhere.
 
Three compounds x,y,z are in ratio 1x,2x,3x take intially after reaction and balancing the ratio of stoichiometric coeffcient ratio 2,6,3 he said y is limiting reagent but i do not know how
 
@M.A.R. spring cleaning froze to death...
 
@Martin-マーチン I was never really there
 
9:25 AM
@Martin-マーチン please i have not teacher to explain this to me
 
Well, it's currently mostly me and ortho doing all the funz in there
@yuvrajsingh I don't know. I really do not understand the question.
 
I repeat the question sir
I have confusion how to find limiting reagent in a balanced chemical reaction
If the initial ratio of the mole of compound 1,2,3 of x,y,z compound of rectant
 
@yuvrajsingh Here's the thing about limiting reagents. You have x, y and z grams of compounds A, B and C which react. That's obviously not proportional to the number of moles, right?
But then, let's say the reaction is something like A + 2B + 3C -> ice cream
 
No sir its intial mole ratio
 
For every mole of A, you'd need three moles of C. That's probably the only new part.
If you end up with 1.5 moles of A but 3 moles of C, C is the limiting reagent, which means it will all get used up before A is finished.
 
9:33 AM
Limiting reagent which is in less quantity
 
@yuvrajsingh No, it's what would finish first
 
How to identify which will finish first
 
Or, if you prefer it that way, 1.5 moles of A is more than 3 moles of C, because C would finish first
@yuvrajsingh divide the . . . psst @Mart . . . number of moles by the coefficient in the balanced reaction
In A + 2B + 3C → ice cream, 3 is C's coefficient
 
@yuvrajsingh Just divide the given moles by the respective stoichiometric coefficients and look for the least value. The one which has least is the limiting reagent!
 
9:37 AM
Are you preparing for JEE?
 
Yes sir jee
I am weak in chemistry
 
Class 11?
 
Struggling with physical chemistry
No sir 12
 
FTR, alt + 26 is a unicode arrow → @Mart. If you go lower or higher you'd find other arrows
Maybe even that bearded modern Robin Hood guy
 
@M.A.R.sir stoichiometric coefficent in a balance chemical reaction refer to the mole of given molecule
Am a right
If than what is meaning of the initial moles that are given
 
9:42 AM
@yuvrajsingh It's just a number that indicates proportion. You can say, for example, that two packets of milk and one banana make a banana milkshake, and if a chemist were to put this in chemical symbols, it'd be 1Banana + 2Milk. It's more convenient to take the proportion to mean 1 moles A to 2 moles of B because that's how everyone does it
@yuvrajsingh That's what you have. You have 3 bananas and 4 packets of milk. How many banana milkshakes can you make?
 
In terms of food, for example, 1A + 2B is the recipe and what you have in the fridge is the real amount of ingredients. It's possible to make food for three and have some of one ingredient left. That's the whole concept.
@yuvrajsingh Bingo. And you have 1 banana left.
 
@M.A.R. I hot your point ,and what meaning of the stoichiometric coefficent what they refer to
 
@yuvrajsingh You can think of reactions as molecules colliding most of the time. Some reactions are also multiple collisions summed up. These coefficients are just memorizable for the most part, or if the balancing doesn't take long, you just balance the reaction to figure out that sum
 
@M.A.R. Sir thank you for clearing my doubt ,your explanation is fantastic
Do you have any notes or something ,which contain problem on stoichiometry please sir i really need it
 
9:48 AM
Unless it's organic chemistry and we're concerned about how the reaction goes, we don't give it much thought there. Some reaction mechanisms for even simple reactions are also really complicated
@yuvrajsingh Sorry, I solved problems from books and they're all in Persian
 
Yup😇 no issue
@M.A.R i have one more question
If you ready to reply
 
@yuvrajsingh sure, if I can
If it's physical chemistry I've forgotten most of that.
 
My describe two method to solve the question
One is poac and second is mole method what is the difference between them
@M.A.R. My book describe sorry i forgot to write describe
 
@yuvrajsingh What does that POAC stand for?
 
Principle of conservation of atom
 
9:57 AM
Mhm
2
Q: Proving 1 = 2 by POAC( Principle of Atom Conservation )

FreelancerI have been told that applying POAC in any equation means conserving the number of moles of an element in both reactant and product . For example : $$\ce{H2 + O2 -> H2O}$$ Here when we apply POAC on oxygen we write : Equation 1 : No. Of Atoms(or moles) of "O" in reactant = No. Of Atoms(or ...

So, um, it's just . . . balancing a reaction?
 
And mole method
 
I've always been taught to use this Pacman method for balancing reactions. Well, the rudimentary ones.
It should ultimately end up in the 1A + 2B + 3C → products thing.
@yuvrajsingh Isn't that something entirely different? It's the same situation as I described above. You use Pacman to find out what the recipe is, that 1:2 proportion. And then you're in a lab and measure how much of A and B you have and that's the mole method
 
What we do in mole method
What my book has @M.A.R. That MxNy then y multiply by mole of M=x multiply by mole of N
MxNy is product
 
I don't know what exactly constitutes mole method but if it is what I think it is you've measured how many grams of A you have and divide it by its molar mass to see how many molecules/particles of A you have
 
10:45 AM
If possible, could anyone please help me in the following doubt.
2
Q: Question on identification of a compound

IntellexQuestion: My Approach: I just found structure Q for all options A, B, C and D for which I have uploaded the structures below with their corresponding options. What I know about Molisch test is it gives the violet ring when an alcoholic solution of 1-naphthol is added to the carbohydrate sol...

 
How is THAT for dead.
I come online for a bloody hour and the transcript is already long enough.
 
 
1 hour later…
12:47 PM
While poac we need to balance the chemical reaction @Mithoron
@Martin-マーチン same question to you
 
what's poac?
And please note that I don't appreciate excessive pinging.
 
Principle of conservation of atom
Sorry for that
 
never heard of that
 
 
1 hour later…
2:16 PM
What is the closest full electron basis analogue to LANL2DZ and defSVP, cause I am trying to perform a energy decomposition analysis using second generation EDA in qchem, but the problem is the orthogonalisation of the frozen energy decomposition step cannot proceed if the basis set has ECPs in it?
 
2:39 PM
Also how do I test whether a minimum energy crossing point (MECP) computed is indeed the point I want and not some other point unrelated to my singlet and triplet structures (because in my PhD structures, it is so common for my structures to converge to the wrong transition state, and I suspect similar thing may occur for MECPs)?
For details, I am using the easyMECP code which implement Harvey's MECP algorithm, but I found the structure converged for the given example case of C6H5 to have nearly the same geometry as the starting geometry, causing me to wonder whether I have set it up properly in my cluster, hence my question
Some more details include the energies of the final steps of the convergences in the singlet and triplet states matches as expected for MECPs, but I am not sure if it is the correct MECP
 
3:08 PM
Another strange feature is that the SCF energies obtained from the structures follow the following ordering:
MECP > Singlet TS > Triplet min
and I cannot think of any way where two parabola can intersect to give something like this
Also, the singlet TS have singnificant triplet character with a <S^2>=1.610
Does that mean there are actually no MECPs that connect the two, but only an avoided crossing?
 
3:31 PM
In other news:
$(╯°□°)╯︵ ^{(╯°□°)╯︵ ^{(╯°□°)╯︵ ┻━┻}}$
when there was a good article that may solve my problem, only to realise the script they use is nowhere to be found in any website
 
 
2 hours later…
5:24 PM
@Engineer You are missing the point. Imagine a man with 1000$\$$. Can he marry? Sure. Will he still be a man? Sure. Will he still be a man with 1000$\$$? Not so sure. — Ivan Neretin 33 mins ago
3
I need a book with all of Ivan's comments.
 
@Loong heh
1) and 2) may be arguable, though :D
Marriage for 1000? though luck kid :D
Some might think that marriage isn't all that neutral to manhood :D
 
hehe
 
Still, somehow House MD always picked more direct metaphors ;)
or maybe not
maybe people around were just smarter then OP :>
 
5:51 PM
@Martin-マーチン Apparently balancing a nonredox reaction got a fancy name
@Loong This guy is my frigging idol now.
 
 
1 hour later…
7:08 PM
Would anyone be willing to help this question:
https://chemistry.stackexchange.com/questions/119462/two-questions-about-mo-diagrams

So that it's got a more descriptive title?
 
@MelanieShebel Well, the first one is a dating question and the second one is a duplicate
 
Yeah, the two different questions threw me off as to how to title it.
 
Either way, it's bloody quantum chemistry where 90 percent of the questions are best responded to as "kid, you're way over your head".
 
Haha, I think Einstein said that to himself in the mirror every morning.
 
@MelanieShebel Nah he drew things.
Have you seen his drawings?
Dang, I'd kill for a relativistic alternate reality where he's a movie director
 
7:19 PM
I haven't seen his drawings, but I'm looking now.
Ever make a search and get way different results than you were expecting and think, "well, wow, what did I expect?"
 
No.
Unless when I searched for Paul Walker crash pics.
 
What happened. Everyone went on a "HAHA Imma post this image and MAR can't see it" spree.
 
 
2 hours later…
9:18 PM
0
Q: Electrons distribution of oxygen atoms in ozone

sanmahaanWhile dealing with the Lewis structure for ozone, most of the explanations show the electron distribution around the 3 oxygen atoms with a single and double bond. But if you count the number of valence electrons of the middle oxygen atom, it will add to 5 valence electrons only, but the number ...

I don't get it. How are they getting these numbers? Doesn't ozone follow octet and Article 13 and GDPR and whatever is thrown at it?
 

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