[sbf5]

Salutations, chemists and students! I come to you today with a request. Allow me to explain my position.

My AP Chemistry teacher has recently informed our class that rather than taking a final exam, we will be designing and executing our own lab experiment! However, should it require anything time-consuming or difficult to obtain, he needs to know our proposals as soon as possible.

I am looking to work with some sort of uncommon metal or metalloid because I find them so interesting. I'm talking about anything from tellurium to lutetium to praseodymium to vanadium. (Please: no iron, magnesium, zinc, or copper. I'm sick of those.)

However, there has to be some achievable purpose in this lab, which is a horrible shame because I simply want to work with unusual chemical elements.

So, I ask you: do you have any ideas for a lab experiment involving some variety of an interesting element I could use? Tungsten or antimony would almost certainly be my first choice, so if, perchance, there's anything you know of involving one of these elements, I would most love to hear it.

Additionally, my teacher informed us that if our labs cannot be completed in a typical classroom setting, there's a chance we could use the equipment at a local university.

Thank you for your time. I look forward to hearing from you.

Sincerely,

~sbf5~

[magician4]

what would the target of your experiment be? prepare some "demanding" substance ? measure some difficult-to-get properties ? have some showeffect with your reaction? (...) etc.
... or are you really up to something "new" , an achievement nobody has reached before, go where no man has been before ?

   pls. be a little more specific about the framework of your task


regards

Ingo

[sbf5]

I am a high school AP Chemistry student who has to design a lab experiment. We just need to observe something or make something happen. It's not anything extreme. It should be akin to the average high school chemistry lab. I just want it to involve an unusual element.

[magician4]

hmm... so, you're simply looking for proposals?
something with an element like vanadium, for example?

so, here's mine:

let's try to make them oxidation states of vanadium visible, shall we?

you prepare
- a solution of sodiumvanadate NaVO₃ in water, add a little sulfuric acid to it. thus, you'll have some VO₂⁺_(aq.) around, in an acidified matrix
  pale-yellow solution , ox. state of V : +5

now you add some zinc (which, of course , immediately will start to produce hydrogen in statu nascendi)

colours will change:

VO²⁺ _(aq.) , blue  , ox. state of V : +4

[V(H₂O)₆]³⁺, green, ox. state of V : +3

[V(H₂O)₆]²⁺, violet, ox. state of V : +2

now, this was the reduction pathway (except of elementary vanadium, that is). what about the other direction, shall we try to oxidize V (+5) further? (you might wish to ask whilst the demonstration). shall we add some known oxidant, like for example H₂O₂ , to acidified starting material?

... and then you again take some sodiumvanadate, acidified by some sulfuric acid, and add some drops of hydrogenperoxide. and:

intense bright red !

( of the complex [V(H₂O)₂(O₂)₂]^2- . and vanadium still is plus 5... )


... and then you might wish to have a discussion why vanadium can't be further oxidized than + 5 , and how colour changes at times might be misleading to wrong conclusions, as a lot may happen ( like , for example, complex formation) besides of redox , with vanadium



regards

Ingo