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
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@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.
@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!
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
@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
@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 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 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
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
I 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 ...
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
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
Question:
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...
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?
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
@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 Neretin33 mins ago
While 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 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 ...
Question:
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...
While 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 ...
The Periodic Table
The Periodic Table