Re: Forensics C
Posted: December 4th, 2010, 10:34 pm
A couple square inches sounds just about right.
the worst ones are like potassium chloride, because the color is a faint purple that 1) blends in with the bunsen burner blue and 2) it's so faint that I can never see it. Sometimes boric acid is pretty bad too because the green shows up not regularly.austinfhs wrote:Sometimes some substances don't burn as readily as they should. Also, you have to consider that what you are burning may not be a pure substance, but mixed with some impure substances. Other reasons could be that you're not positioning the substance within the flame correctly and the flame is not powerful enough. What substance are you having trouble IDing? With enough practice you should be able to identify the flame tests, even though there is not much color coming out. Even though there is no real trick to tell the flame color, so it is more accurate if you use chemical reactions to identify the powder. You can Google some flowcharts that can help you do this, depending on the substance at quest.
I think you may need to be a little more patient with your flame tests; boric acid and potassium chloride are extremely distinguishable! Those, combined with lithium chloride, make for an easy test!personasaurus rex wrote: the worst ones are like potassium chloride, because the color is a faint purple that 1) blends in with the bunsen burner blue and 2) it's so faint that I can never see it. Sometimes boric acid is pretty bad too because the green shows up not regularly.
Thank you so much!jazzy009 wrote:I think you may need to be a little more patient with your flame tests; boric acid and potassium chloride are extremely distinguishable! Those, combined with lithium chloride, make for an easy test!personasaurus rex wrote: the worst ones are like potassium chloride, because the color is a faint purple that 1) blends in with the bunsen burner blue and 2) it's so faint that I can never see it. Sometimes boric acid is pretty bad too because the green shows up not regularly.
Also (reading earlier posts), all sodiums will burn orange. Not only that, but the sodium stains your loop (what fun!). So if you're getting a constant orange and can tell it's a sodium, you definitely need to clean your loop with acid before running another test with it.
It's the little wire thing that you use to hold the powder solutions to conduct flame tests.personasaurus rex wrote:What "loop" are you talking about? o_O
oh wow whaaat? we just use wooden splints hahahhahahahaa... could that be affecting our results?austinfhs wrote:It's the little wire thing that you use to hold the powder solutions to conduct flame tests.personasaurus rex wrote:What "loop" are you talking about? o_O
Seeing as the wood probably burns ... yes, although a pure metal loop still burns orange. However, your results should be much clearly using the loop because it will burn the powder more than the wood that you have been using.personasaurus rex wrote:oh wow whaaat? we just use wooden splints hahahhahahahaa... could that be affecting our results?
oh my... that would eliminate a lot of the problems we're having... thank you so much!! =]austinfhs wrote:Seeing as the wood probably burns ... yes, although a pure metal loop still burns orange. However, your results should be much clearly using the loop because it will burn the powder more than the wood that you have been using.personasaurus rex wrote:oh wow whaaat? we just use wooden splints hahahhahahahaa... could that be affecting our results?