Sciencemadness Discussion Board

Experiments to do with potassium tetraborate?

valeg96 - 17-4-2014 at 11:34

I've been given for free a kg of potassium tetraborate, analysis grade. What can I do with it? There's almost nothing about it on the net, not even on wiki. Can I synthesize other compounds with it? I've also been given mercury (II) chloride ( 1g/L, 100mL) and zinc sulfate (200g), both analysis grade.

Brain&Force - 17-4-2014 at 11:36

Try a small flame test with it - I'm curious about what color it would be. Sodium borate produces a yellowish flame; I think potassium borate forms a green flame because the potassium lines are very weak.

Artemus Gordon - 17-4-2014 at 16:36

Na+ ions and K+ ions are pretty similar. I would think anything you can do with sodium tetraborate could be done with potassium tetraborate. <a href="http://chemistry.about.com/b/2012/10/01/download-the-golden-book-of-chemistry-experiments.htm"> The Golden Book of Chemistry Experiments</a> shows how to make boric acid, and there are several places where you can find recipes for Silly Putty or slime, including About.com Chemistry.

Out of curiousity, did the person who gave it to you tell you what they intended to use it for?




[Edited on 18-4-2014 by Artemus Gordon]

sasan - 17-4-2014 at 22:46

valeg96 react the tetraborate with hydrochloric acid to obtain boric acid,heat the boric untill B2O3 forms
and you can solve boric acid in the methanol(sulfuric acid catalyst) to gain trimethyl borate,it ignites with a very pretty green flame
I have too much sodium tetraborate inhand too,I reacted it with soluble metal salts to make insoluble metal borates like copper tetra borate,Iron(ll)tetra borate,lead tetra borate and...

nezza - 18-4-2014 at 00:03

Alkali tetraborates are used in the borax bead test for coloured metal cations. Borax is taken up onto a platinum loop and melted. This is dipped into a sample of the metal salt to be tested and remelted. Metals with coloured ions (Copper, cobalt etc) give an attractive colour to the transparent borax bead.

HgDinis25 - 18-4-2014 at 02:45

If you wish, you can go all the way to elemental Boron. React with a strong acid to obtain Boric Acid, Dehydrate the Boric Acid to obtain B2O3 (Boron Oxide). Make a thermite out of the oxide and obtain Boron xD
There is actualy a great video explaining this:
http://www.youtube.com/watch?v=0QBCyOrjR2o

chloric1 - 1-5-2024 at 13:44

Actually, I’m about to make potassium tetraborate from boric acid and potassium hydroxide! I made a great brazing flux with borax, trisodium phosphate and boric acid but the yellow flame is a bit much. I still get better results than some commercial fluxes but I want to try a potassium version. I have 75% phosphoric acid and nearly 2 pound of KOH flakes. I’ll make potassium tetraborate and tripotassium phosphate. The K3PO4 is VERY soluble so I’ll keep that part in the aqueous phase and add to the two powdered ingredients with any additional water if needed to mix.