Sciencemadness Discussion Board

Solutions and precipitates - an overview

woelen - 2-10-2005 at 13:33

I'm working on an overview of ions and precipitates of all common metals and some less common metals. I try to make the overview as complete as possible (all possible oxidation states, common complexes, etc.).

I completed the work for all first-row transition metals, except scandium (I don't have that :( ).

On the web page below, you can see what I've written and there are lots of pictures. Currently I'm also working on pages for the metals, which are shown in bold-face, but with no link (yet). I have the chems, now I have to find the time ;) .

http://woelen.scheikunde.net/science/chem/solutions

If you find any errors or serious omissions, please let me know.

Fleaker - 2-10-2005 at 17:20

Great job and very convenient for us all! Since you're recording observations as you do the reaction it should be relatively error-free. Thanks!

Wonderful!

PugconDoin - 2-10-2005 at 17:21

I just wanted to say that your page is great! Thanks for using such high-quality images, they make for much more interesting reading and easier visualization.

^_^

The_Davster - 2-10-2005 at 17:37

I like your idea here.:)

Only thing I can say is that I find it strange your manganese sulphate is not pink, my saturated manganese acetate solution is very pink. Also you are forgetting Mn2O7 in your section on Mn7+ oxidation state, green by reflected light, red by transmitted light. I gues it is an exception to the purple rule.

Looks like you have started on the lanthanides as well. I cant wait to see them.:D

chemoleo - 2-10-2005 at 19:17

Very nice work Woelen, the pictures are entrancing!

I agree on rogues note, the MnCl2 * xH2O is very pink (lab grade), it couldnt be any pinker!

Maybe you'd like to contribute some of your work including pictures to BromicAcid's book?
I am sure he'd be delighted, so would those who read it!

woelen - 3-10-2005 at 04:15

Thanks for your positive responses.

I'll look into the color of the manganese (II) salts. Your observations surprise me. I've never seen it as real pink, except in the dirty-pink MgS. The manganese sulfate I have is very pale pink as you can see on the pictures and solutions of this are colorless. So, it sounds interesting that MnCl2.xH2O is as pink as pink can be.

I don't have MnCl2.xH2O, but what I can do is very thoroughly mix my MnSO4.H2O with KCl and add a very small amount of water to get the extra crystal water and see if this becomes pink.
Do you also get a clearly visible pink solution if you dissolve the MnCl2.xH2O? If I dissolve MnSO4.H2O in water, then even at very high concentration, the liquid still is (almost) colorless.

woelen - 5-10-2005 at 10:06

I have taken the comments on Mn2O7 into account and now this is added, together with some nice pictures, demonstrating the green color by reflected light and red by transmitted light (I did not even know that, so thanks for pointing me in that direction :D ).

I also updated the page on chromium. This now mentions the volatile CrO2Cl2 and the orange/brown gas, which can be made from this (really nice stuff, albeit a little bad for your health). It has a sweet smell though :P . Just look at the end of the page.

If someone out there can give suggestions on the pink color of manganese (II) I would be pleased. I tried to reproduce that, but I only get colorless manganese (II). Also mixing of MnSO4.H2O and KCl and heating and letting cool down again does not give me a pink compound. The only pink Mn(II) compound I can make is MnS :( .


@BromicAcid: If you want to use parts of this overview for your book, please U2U or send a mail.

[Edited on 5-10-2005 by woelen]

The_Davster - 16-10-2005 at 22:56

I think I know what is going on with the Mn(II) ion colours: We both are using concentrated solutions, however yours is in a testtube where as mine is in a 250mL beaker, the colour difference is simply a result of looking through a greater distance of solution.

Kinda interesting watch the pink slowly dissapear as my Mn(CH3COO)2 is finishing up evaporating and parts of it are turning (nearly) white.

Also completly off topic but, freshly filtered and airdried neodymium carbonate is such a shiny purple... so beautiful...:D