posted by Sarah on .
I have an lab I am doing in inorganic chemistry and it is where we synthesized our own compounds by adding together a bunhc of differnt ones. We are now asked to calculate the theoretical yield and they tell us which one is the limiting reagent. My question is about the equation...because in order to determine the yield you need to balance the equation first...but we are adding a whole bucnh of things together to get this product, so I don't know how you are supposed to determine the other prodcuts...would I take each part of adding together and find the products, and then those products lead to the next product until the one left is the one where I have the last product to make my new substance? But then how would I tell what the intermediate prodcuts are? Ahhh im so confused, anyways here are the compounds added:
Cl2H8MnO4 + C2H9NaO5 then once that is together you add C5H8O2 then to that product you add KMnO4 then to that product you add more C2H9NaO5 and the compound I made was C15H21MnO6 but I don't know how I determine what the other products inthe soultion were (cause we filtered it)
I have gone through the compounds listed in your question (with some consternation). I have tentatively identified Cl2H8MnO4 (probably) as manganese(II) chloride tetrahydrate.
I think C2H9NO5 probably is sodium acetate trihydrate. There are several possibilities for C5H8O2 so you need to be more specific about what actual compound you used. It could be the ethyl ester of 2-propenoic acid as well as a number of other compounds. I think C15H21MnO6 may be manganese(III) acetyl acetylacetonate. My suggestion is that you try to fit these possibilities into the scheme of what you did. Good luck. This is not an inorganic problem entirely.
P. S. I have been told that this is the NEW way of listing compounds. All I can say is that I'm glad to be retired. H4N2O3 NEVER will take the place of NH4NO3 in my book.
Unfortunately the new way does suck and makes no sense, I try to revert back to the old way as much as possible. I still have a concern though. When I am trying to figure out all of the products that you get when you add these together and I only know one. I know that out of this I produced solid Mn(acac)3. I need to balance this to determine the yield, and I know that the limiting reagent will be the potassium permanganate. I know that I can balance by using oxidation states, but if I only know the one product that has the one change can I still balance it since all I need to know are those 2?
Often that can be done; however, in this case I don't think it will work since you are looking for percent yield.
Frankly, I doubt that KMnO4 is the limiting reagent. I suppose it could be but that is for the purpose of oxidizing, probably Mn(II) to Mn(III).
In the scheme of things, 1 mole Mn = 1 mole Mn(acac)3. You need to determine where the acac came from to know its stoichiometry. Which means, of course, you need to know the intermediates.