I have a problem that has been driving me crazy trying to solve, and I was wondering if someone could help. The problem is this: "Given the reaction: CuSO4 + 4 NH3 ----> Cu(NH3)4SO4, if 10 grams of CuSO4 reacts with 30 grams of NH3, what is the theoretical yield of Cu(NH3)4SO4, what is the limiting reactant, how many grams of the excess reactant is left over, and if the actual yield is 12.6 grams, what is the percent yield?" I don't know if it's hard or not, but I keep getting stuck after finding the theoretical yield (176.24?). Could someone help?
(Also, I'm finding the theoretical yield by adding up the atomic masses of CuSO4 + 4 NH3. Is this where I am possibly screwing up?)
Yes, we can help. You posted this earlier and Bob Pursley told you that 176 g sounded high to him and for you to show your work and we would find the error. So show your work how you obtained the 176.24 g theoretical yield.
Ok. For the theoretical yield I added up the atomic masses for CuSO4 + 4 NH3. Cu (12.01) + S(32.07) + O4(64.00) + (NH3(17.04) * 4 = 68.16) = 176.24. Am I finding the theoretical yield the wrong way?
Let me help you on this...
To find the limiting reactant first of all.
-You have to first find the moles you have of each reactant.
- then go and find out how much of each reactant do you need to consume the other reactant
- then compare it to how much moles you do have of each and the one that needs more to consume than you have is the limiting reactant
- use the limiting reactant to go and solve for how much is produced.
- convert moles to grams produced
I'll start with this and PLEASE post your work as I'm NOT going to do all the work =)
NO NO NO read what I posted below please
First, that's not how to determine the theoretical yield.
Second, Cu is 63.5 something and not 12.01. You have used the atomic mass of C and not Cu.
Ok, I will. Also, could someone tell me how to find the theoretical yield, since I'm apparently doing it wrong for some reason.
I just gave you instructions for finding the theoretical yield Josh.
Uh, christina, you just told me how to find the limiting reactant, not the theoretical yield.
-You have to first find the moles you have of each reactant.
- then go and find out how much of each reactant do you need to consume the other reactant
- then compare it to how much moles you do have of each and the one that needs more to consume than you have is the limiting reactant
theoretical yield is:
- use the limiting reactant to go and solve for how much is produced. (theoretical yield)
- convert moles to grams produced
Post work based on steps and if you have problems with the steps just post what you get up to and I'll analyze. =)