I've been taking a lab at University for this semester(Inorganic 1), and I feel like I'm incredibly behind.
I've also looked and flipped through the text, but I still can't seem to figure out some problems like how to see the formation of certain complexes.
I have a couple of questions that I'd like pointers on to figure out for my lab report(Which was due yesterday, so I already had to turn it in with a couple of blanks. Oh well, my fault.)
The experiment was basically the preparation of copper(I) iodide with copper metal and a few other compounds, and the post lab and my attempts are as follows(The lab was already due, but it's nagging me that I didn't know how to do these.):
Explain the effect of adding a drop of acetic acid: To remove copper oxides on the copper film.
Balanced eqn of CuO with acetic acid. Balanced eqn of CuCO3
with the acid.
COOH + CuO -> (CH3
The second equation I found online after a ton of searching, but I'm not sure how exactly they came up with it. Is it just known that the equation would form carbon dioxide and water, leaving behind a copper acetate? Is there a step-by-step process of elimination I can employ?
Balanced eqn between copper(II) acetate, sodium iodide, and copper
+ NaI + Cu(s) -> This is another issue I have. How do I know what happens? Considering that this includes three different compounds, what exactly can I do to know what will react?
Explain why no iodine escapes, nor condenses in the upper cold part of the tube while heating the mixture I2
- I'm assuming it's because iodine has reacted with the copper/rest of the solution, so gaseous iodine wouldn't escape while heating the mixture. I know that CuI is soluble in iodide, so would the sodium iodide react with the copper metal to make CuI and then that's what causes iodine to react and not escape?
Why is CuI soluble in concentrated iodide solutions?
- Because...it is? I'm not too sure about solubility in solvents besides water, unfortunately.
When the resulting 'diluted' NaI solution is concentrated and re-used for a further preparation of CuI, the yield eventually might go beyond 100%. Why?
- When I originally saw my yield go to high values I assumed it was just because of mechanical error and some of the excess washing materials used for the precipitated CuI got left over and weighed as well. Aside from that I'm not too sure what else would cause this.
Why are copper(II) and iodide incompatible in acid media and compatible in ammonia media.
- I wasn't aware they were incompatible. I thought in most any solution it'd just be Cu2+
which decomposes to CuI and I2
Predict adding PPh3
to suspension of CuI in CH2
- So I know PPh3
is triphenylphosphine, CH2
is dichloromethene. What would actually happen?
If I recall correctly, phosphines are easily oxidized, so would the triphenylphosphine act as an oxidizing agent for the copper?