I'm not sure what it is

[Oban Kobi]

I mixed HCl and KNO3 and the solution slowly became purple. The acid is blue, mostly because it's not just acid and water, but there is nothing else in it other than coloring and I imagine glycerin to make it thicker. Anyway, what is the purple? My first thought was Potassium something, probably Chloride, but I'm not sure. I searched Google and read a thread about it on this site, but neither helped much. I did find that if it in fact made nitric acid, it would react with the remaining hydrochloric acid and produce aqua regia at least according to Wikipedia, which isn't entirely reliable. Aqua regia is red(ish) and mixed with blue would make purple (that's right, I know my colors:-p) I would appreciate it if some one would explain to me what the result is.

[YT2095]

there`s not really enough data as to what the dye and thickener is in the HCl, do an experiment and add a little H2O2 to some of the HCl and see it that also goes purple.

if it does then it`s the dye being oxidised.

[Oban Kobi]

Ok, thanks, I'll go try that real quick, I have to go, though I'll post what happened in case any one else cares to know

 

Ok, it did not turn purple when I added the H2O2. The purple color from before has since disappeared, and is now more pale yellow. Also, when I added the acid to the KNO3 it gave off a gas, I imagine hydrogen and chlorine, which would probably recombine to become once again HCl, which would explain that oh so pleasant smell. Any thoughts?

 

Alright, I tried it again. I'll write down everything I did.

First I placed about a gram of KNO3 in a glass test tube. I then poured about 15 ml of 20% HCl into the tube. It became purple, starting at the bottom where the KNO3 rest, and released a gas, I think HCl, judging by the slight burning it caused in my nose, which made me hold it a bit further away. I then used a syringe to pull half of the purple liquid out of the tube, and left the rest in there. The liquid in the tube slowly lost it's color, and became a bit of a light orange. The liquid in the syringe was stoppered, and retained its color. I emptied half of the syringe into another test tube, and gently heated it to avoid boiling. It's color changed from purple to a yellow green, and smelled a bit like chlorine. It is still yellow green, and the liquid in the syringe slowly became that same yellow orange color. That's about it. So now I have two questions: What would mixing HCl and KNO3 result in? Me thinks KCl and HNO3, which would combine with the remaining HCl and make aqua regia, which would explain the orange color. But why was it at first purple?

What is the yellow green liquid? I think it's probably chlorine, but then where did everything else go? I didn't heat it insanely hot, just a bit.

I appreciate any help or explanations you can give, thanks

[Ladeira]

What would mixing HCl and KNO3 result in? Me thinks KCl and HNO3, which would combine with the remaining HCl and make aqua regia, which would explain the orange color. But why was it at first purple?

 

Maybe I'm saying idiot stuff, but I'm not so sure HCl and KNO3 react. There cant be a double replacement reaction since it doesn't make anything like a weak acid or a precipitation.

 

What is been discussed KNO3 or HNO3?

 

Aqua regia is made with the proportion 1:3, HNO3 and HCl, in volume.

 

Hope I could help you some. I cant explain the purple color, are the reagents pure? a "contamination" may be the key.