jgourlay - 17-9-2008 at 06:06
I call it paleochemistry. Might as well characterize it as "don't know what I'm doing and don't have the right equipment chemistry" but, it's what
I've got!
In another thread about analyzing the composition of faux KN03, one of you suggested the nitrate test. For that I need the ferric sulphate.
Here is what I have: good quality steel wool, sulphuric acid of frightening but unknown strength, an electronic balance that can weigh to within +/-
.1 grain (will measure in grams) graduated plastic labware, "gross" pH paper (1-14). I also have typical household chemicals: bleach, baking soda,
purple cabbage, etc.
From where I am, what is my route to getting the ferric sulfphate necessary for the nitrate test? Now that I think about it, I guess the root
questions are: how do I determine the molarity of the acid, and are my instruments good enough to get to a final "good enough" nitrate test answer?
By the way, someone here (I think) turned me on to the idea of adding sulphuric acid to sugar. This gleefully delighted my 7 year old who now takes
tremendous pleasure in dragging every houseguest over to the display cabinet where he has stored his "chemical poo".
DNA - 17-9-2008 at 06:12
jgourlay you'dd better get some iron for your ferric sulphate since steelwool contains iron but will not give you like good ferric sulphate.
Better try a iron nail, then you can dissolve that in sulphuric acid while you warm it, then you will have a solution of ferric sulphate which can be
evaporated untril dryness then you will have ferric sulphate add some solvent, and decant to wash away excess sulphuric acid and done.
panziandi - 17-9-2008 at 06:18
Or you can get iron oxide (rust) as a pigment in ceramic stores and online etc. You can get ferrous sulphate in garden centres very cheaply and be
oxidised to ferric sulphate if that is what you need.
ScienceSquirrel - 17-9-2008 at 06:33
You need ferrous sulphate aka iron II sulphate for a brown ring test, NOT ferric sulphate aka iron III sulphate.
not_important - 17-9-2008 at 06:41
And to get ferrous Fe(II) salts you want to have an excess of the metal, as well as limiting access of air - a cotton ball stopper or leaky cork will
do.
I don't know why DNA think steel wool won't do, there's carbon and a bit of alloying metals in it, but nails are generally steel too. The large
surface area will give faster reaction when using steel wool.
ScienceSquirrel - 17-9-2008 at 07:38
And here is a nice recipe complete with pictures.
http://www.crscientific.com/ferroussulfate.html
You can even impress your son by making some crystals!
Thanks guys!
jgourlay - 17-9-2008 at 07:43
Thanks gents!