Chemical Forums
Chemistry Forums for Students => Inorganic Chemistry Forum => Topic started by: PetraJoerg on December 01, 2017, 10:49:26 AM
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I've been assigned this exercise but I don't know how to do the experiment without any accurate indications of quantity or concentration:
Sa Cu(L-asp)(H20)2 was obtained from the reaction
of stoichiometric quantities of L-aspartic acid and copper basic carbonate
in a water solution at 100 OC. The solution, taken to pH 5 by adding
nitric acid, produced good single crystals when cooled to 10 "C in 1 day
or after several days of slow evaporation at room temperature. They
grow as thin sheets parallel to (IOO), elongated along b, with borders
bounded by faces parallel to (001) and (010) planes. The weights of the
largest single-crystal samples obtained up to this moment are less than 1 mg.
Does anybody know how much aspartic acid of which concentration I am going to need
and what amount of copper basic carbonate and water??
Thanks in advance
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Hi there, PetraJoerg:, I've gone and moved your question here to Inorganic Chemistry. Although your topic involves organic molecules, we tend to put complexies of metal ions here.
You've got a type of question that comes up often on this board, confusing many students -- they've been given a ratio, and they don't know how to figure out -- how much.
Unfortunately, we can't help because -- we don't know. How much do you need? Sometimes, when people really don't know, I say: make 100 grams. Does that sound like too much? Make 10 grams then, or 1 gram or even 0.1 g. Do you want to make a kilogram? I'm not the one who's going to discourage you -- although the reaction may fail, because large volumes may not behave ideally. Which is part of the problem, you don't want to go too big, but how big is too big?
OK. Time for me to put on my Moderator: hat. Some new people hate this, but I wouldn't be doin' ma jerb if I don't let people know ...
Greetings, PetraJoerg:, I'd like to welcome you to the Chemical Forums, I can see you're new here, but I want to ask you to review our Forum Rules{click} (http://www.chemicalforums.com/index.php?topic=65859.0). You already accepted the rules when you signed up for our forum, and you have to follow them, whether you agree with them or not, or even if you're unaware of them.
We want to see you do some work, on your own, and we'll help. We don't dump complete answers, for anyone, not for a high school student, nor a hard-working professional, nor even the home chemist working on their newest invention.
*Ahem*
You've cut and pasted the assignment. And I suppose we should be grateful for the extra information. But this doesn't show any of your work. Example:
... They
grow as thin sheets parallel to (IOO), elongated along b, with borders
bounded by faces parallel to (001) and (010) planes. ...
This bit doesn't really help you understand the question you have. Didn't you notice that? If you really read the question, and tried to understand it on your own, you might have left that off. This looks to me like you're not trying at all.
Now taking this part:
Cu(L-asp)(H20)2 was obtained from the reaction
of stoichiometric quantities of L-aspartic acid and copper basic carbonate
in a water solution at 100 OC.
What would be stoichiometric quantities of aspartc acid and copper salt to produce 10 grams of product? What does stoichiometric mean? Please don't tell us you know what it means or copy the text of a definition -- actually write out the math where you compute the stoichiometry in this case.
I don't think you would have gotten this assignment if the instructor didn't expect you to be able to solve this. So lets see your attempt. We're here to help you if you get stuck.
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Is copper carbonate soluble?
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Is copper carbonate soluble?
Does it have to be to follow the O.P.'s protocol?