Question

Please help, I have been trying to figure this out for some time:
For a lab I dissolved Calcium chloride with sodium carbonate each in water, then poured them into a funnel and filtered out a white pigment. I need to calculate the percent yield, but what is the white pigment. Is it calcium carbonate, sodium chloride, or something else?

Answer 1

The white precipitate, insoluble in the solvent, is calcium carbonate. The NaCl is soluble, CaCl2 is soluble, and Na2CO3 is soluble.

Answer 2

ok thank you with that part, but I still don't understand how I find the percent yield

Answer 3

You should have dried the precipitate (ppt) and weighed it. I don't know how carefully the experiment was controlled but I would have weighed the paper first so I could subtract the mass of the paper from the mass of the paper+ppt. At any rate, this gives you the ACTUAL yield.
The theoretical yield is calculated from stoichiomtery.
Na2CO3 + CaCl2 ==> 2NaCl + CaCOO3.

I assume you know how much Na2CO3 OR how much CaCl2 you started with. Either a weight of one or both or a molarity and volume of one or both. CaCulate the theoretical yield from that, then
percent yield = (actual yield/theoretical yield)*100

Answer 4

thanks