Problems with chemicals

[margsu]

I have a few problems with chemicals.

So I have concentrated HNO3 65% and ususal 33% HCL. If I want to make AR how much I must take HCL. At the moment I make ususal 1:4 AR and there is quite violent HNO3 reaction. So I have question about H2O2. I have 50% peroxide so how much I must dilute it if I want to get about 10% peroxide. At the moment I dissolved some goldfoils in AP.

 

[goldenchild]

What exactly are you asking here? Are you asking how to dilute AR or how not to get a violent reaction when mixing the 2 acids? Is the violent reaction caused when you mix the acids or when you use the acids on your metal(s)? When I make AR I measure out the amount of HCL needed in a measuring cup and add it to the metal(s). I then measure out the nitric (you can use the same cup) and SLOWLY add the nitric to the HCL in small increments letting the reaction subside between increments. Then slowly heat. Hope this helps.

 

[butcher]

See also GSP's suggestion on minimal use of nitric and heat, Harold has also gave good input on this and some great information on eliminating the nitric with gold.

I am not sure but others may have a way to do this with math, I think this would work if you don't get a better answer. If you are asking how much water to add to your 50% peroxide solution, to get a 10% solution.
50% H2O2 and 50% water for 100% solution, if I had one cup of this solution, and added a cup of water I would Have 25% H2O2 in two cups of solution, now if I added two more cups of water I would end up with 12% H2O2 in 4 cups of solution.

Come on math Wizards show us a better way.

 

[margsu]

thanks. At the moment I dryed some AR. I have a lot of brows seddiment which is not dissolved in muriatic and nitric. Firstly I washed with muriatic and second time with nitric. Is that gold or may be some other PM? Can nitric dissolve rhodium and palladium? I processed only computer pins and processors.

 

[butcher]

nitric can dissolve Pd.
Rh will not dissolve in nitric, HCl, or aqua regia.
this brown powder is most likely a dirty gold, see your other question on this for more information, and please only one post on a subject, someone will see it and give you help, putting the same question up in several posts only confuses you and others.