[red_hypergiant]

Hello,

I'm not sure if any of you are familiar with the IB, but I am currently working on my Chemistry IA and I'm having an issue (it'll probably sound stupid). Anyway, I carried out an experiment in which I had 5 transition metal sulfates (CuSO4, Fe2(SO4)3, KCrS2O8, MnSO4 and diammonium iron(II) sulfate) and using titration, I added different volumes of NH3 and (NH4)2SO4 to the trans metal sulfates. I did about 8 trials of each metal (so 8 different volumes of NH3) and I used samples of each to record their colorimeter readings. So the key data that I have are the volumes of the trans metal ions used, the volumes of NH3, the average colorimeter readings, and also a graph of the colorimeter readings plotted against the volumes of the metal ion. And for some crazy reason (probably my brain not being competent enough ) I just can't come up with a research question. I did an experiment without concretely knowing the purpose of it! So yeah, I'm still trying to figure it out and I guess I need some help. I'm thinking perhaps how does the ion size affect....the addition of the ligand??? Oh god...I don't know. (thanks for any help in advance)

[Vidya]

Yes you can discuss how the size and charge on the central ion can effect stability and formation of the complex...it is a very common concept.

[red_hypergiant]

Yes you can discuss how the size and charge on the central ion can effect stability and formation of the complex...it is a very common concept.

Okay, and how would I use my colorimeter data? (I know it's a very common concept haha) Is it something to do with the formula of the complex ion?

[Arkcon]

Hello,

I'm not sure if any of you are familiar with the IB, but I am currently working on my Chemistry IA and I'm having an issue (it'll probably sound stupid).

Uh, some of us may, but not really pertinent, but no question is ever stupid.  But whatever, thanks for whatever introduction you feel like starting with.  I guess.

Anyway, I carried out an experiment in which I had 5 transition metal sulfates (CuSO4, Fe2(SO4)3, KCrS2O8, MnSO4 and diammonium iron(II) sulfate) and using titration, I added different volumes of NH3 and (NH4)2SO4 to the trans metal sulfates.

Pretty clear.

I did about 8 trials of each metal (so 8 different volumes of NH3) and I used samples of each to record their colorimeter readings. So the key data that I have are the volumes of the trans metal ions used, the volumes of NH3, the average colorimeter readings, and also a graph of the colorimeter readings plotted against the volumes of the metal ion.

Still pretty clear.  A little unsure now where you get "about" from: 8 trials, or 7 or 9 trials, or you're not sure, or you lost count, maybe one failed, or ... what exactly?  Why say "about".  Are you trying to be casual or cool, or why would you type that?  Just letting you know, "about" isn't the best word to use in science, unless its unavoidable, but "about" in the number of trials leaves us wondering where else we're going.

And for some crazy reason (probably my brain not being competent enough ) I just can't come up with a research question. I did an experiment without concretely knowing the purpose of it! So yeah, I'm still trying to figure it out and I guess I need some help.

This sort of problem will strike at this level of science instruction.  Try not to feel too flustered.

I'm thinking perhaps how does the ion size affect....the addition of the ligand??? Oh god...I don't know. (thanks for any help in advance)

Here's an idea:  start by building a table, or a series of tables -- metal ion, choice of ligand, volumes and your colorimeter result.  You might treat it as a "black box" for now.  You did something many different ways and you got a certain number reading out of the instrument.  Later, we may want to see if we can understand the instrument better -- especially if we can't pull any sort of trend out of your data.

[red_hypergiant]

Uh, some of us may, but not really pertinent, but no question is ever stupid.  But whatever, thanks for whatever introduction you feel like starting with.  I guess.

It is pertinent because it gives a sense of the level of Chemistry I'm working at and the reason as to why I am asking the question. But whatever, some people just can't appreciate that, I guess. Perhaps I should've tailored my introduction to your satisfaction. Too late for that, I guess.

Pretty clear.

That's good.

Still pretty clear.  A little unsure now where you get "about" from: 8 trials, or 7 or 9 trials, or you're not sure, or you lost count, maybe one failed, or ... what exactly?  Why say "about".  Are you trying to be casual or cool, or why would you type that?  Just letting you know, "about" isn't the best word to use in science, unless its unavoidable, but "about" in the number of trials leaves us wondering where else we're going.

Oh yes, I was definitely trying to be cool. I say "about" in just about every sentence, and trust me, it gets me places. But okay, if you wish to be so pedantic, I'll kindly give you an explanation. As I was following a standard procedure, the volumes of NH3 and (NH4)2SO4 weren't necessarily sufficient for every single transition metal I had (specifically the last two I mentioned). I consulted my teacher regarding that issue, and she gave me the green light, so on I went. Now, since I knew the volumes of NH3 was not going to be enough for the last two, I only did about 3 trials (oh woops, there I go again) just for the sake of certainty, and wrote 0 for all the colorimeter readings. But then again, is all that information really pertinent to the question at hand? You tell me.

This sort of problem will strike at this level of science instruction.  Try not to feel too flustered.

Oh, I'm blushing, how embarrassingly stupid of me.

Here's an idea:  start by building a table, or a series of tables -- metal ion, choice of ligand, volumes and your colorimeter result.  You might treat it as a "black box" for now.  You did something many different ways and you got a certain number reading out of the instrument.  Later, we may want to see if we can understand the instrument better -- especially if we can't pull any sort of trend out of your data.

Okay, I see you've finally made an attempt to help me out. That's kind of you, I guess. Anyway, first off, I didn't vary the ligand, I used NH3 for every single transition metal. Secondly, you asked me to build a "table, or a series of tables", and I'll just let you know that I already have, and as I said, I even have graphs which are even more helpful. But thank you for the suggestion.

[red_hypergiant]

{MOD Edit: auto-quote removed}

Update:

Is it possible, and how can I use the colorimeter readings to work out the formula of the complex ion? I was wondering if perhaps if it'll have different formulas at different points on the graphs, then I could use that info to work out the ratio of NH3 to water and work on from there.