LingLing Posted July 17, 2011 Posted July 17, 2011 I recently purchased 5 pounds of KClO4 and KNO3 which arrived in 1 pound bags each in a metal paint can from the distributor. Each bag was clearly labeled. However, I mixed up about 10g of flash powder to test the KClO4 and the results weren't what I was expecting. The powder burned very slowly and very red. I've never seen flash powder burn red, so I was wondering if I may have been shipped Strontium Nitrate instead? I don't mind very much as I can use the Strontium, even though it's a little cheaper, but I was wondering if there was any way to know for certain. Is there any test I can perform to determine if the bags contain KClO4 or Strontium? TIA
Seymour Posted July 17, 2011 Posted July 17, 2011 I recently purchased 5 pounds of KClO4 and KNO3 which arrived in 1 pound bags each in a metal paint can from the distributor. Each bag was clearly labeled. However, I mixed up about 10g of flash powder to test the KClO4 and the results weren't what I was expecting. The powder burned very slowly and very red. I've never seen flash powder burn red, so I was wondering if I may have been shipped Strontium Nitrate instead? I don't mind very much as I can use the Strontium, even though it's a little cheaper, but I was wondering if there was any way to know for certain. Is there any test I can perform to determine if the bags contain KClO4 or Strontium? TIA So long as you are confident that it's either Strontium nitrate or Potassium perchlorate, you can easily tell the difference between them by adding a little to some cold water. KClO4 won't dissolve appreciably, but the Sr(NO3)2 will. However, there are many things that it could be that dissolve in water. When you say "very red", do you mean in comparison to other oxidiser/Aluminium mixes? While you'll certainly get some red colouring from such a mix, when you compare it to a good red mix, I'd describe it more like "Somewhat Redish"
superstring Posted July 17, 2011 Posted July 17, 2011 TIA, you might try the test from Wikipedia listed below. If you suspect Sr. go ahead and make a simple star or flare mix. Using some magnesium in conjunction with strontium nitrate would produce a brilliant red. Burn rate would depend on type of fuels used as well as fuel/oxidizer ratios. Have fun! chemical detective. Brown ring testA common nitrate test, known as the brown ring test[1] can be performed by adding iron(II) sulfate to a solution of a nitrate, then slowly adding concentrated sulfuric acid such that the sulfuric acid forms a layer above the aqueous solution. A brown ring will form at the junction of the two layers, indicating the presence of the nitrate ion.[2] Note that the presence of nitrite ions will interfere with this test.[3] The overall reaction is the reduction of the nitrate ion by iron(II) which is oxidised to iron(III) and formation of a nitrosyl complex. NO3- + 3Fe2+ + 4H+ → 3Fe3+ + NO + 2H2O[Fe(H2O)6]2+ + NO → [Fe(H2O)5(NO)]2+It should be noted here that Fe is not in its usual +2 oxidation state but is in a +1 Oxidation state and the NO is also in a +1 oxidation state. From : http://en.wikipedia.org/wiki/Nitrate_test#Devarda.27s_test
LingLing Posted July 17, 2011 Author Posted July 17, 2011 Thanks for the replies. It looks like I blew it with my assumptions, though. I was using some chemicals that a friend gave me and the aluminum I used seems to be the culprit. The jar wasn't labeled other than 'aluminum', and it was very dense and light colored. When I used a darker 425 mesh aluminum, the KClO4 performed as expected. I didn't realize that aluminum mesh size would make that much of a difference. Thanks again.
TigerTail Posted July 17, 2011 Posted July 17, 2011 Slow burning could be caused by spherical Al, but what made it red? Was it more like a potassium purple or what?
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