Why Aren't My Methanol Flames Changing Colors with Different Salts?

[vaselinessa]

I'm trying to get a variety of colored flames by dissolving salt and methanol (after the fashion of this YouTube video et al.: http://www.youtube.com/watch?v=eRNLqTfIjQo").

I'm doing halfway alright with strontium chloride solution and boric acid solution, but having some trouble: the boric acid solution burns green for a little while but then turns yellow; the strontium solution is a bit dodgy, giving only intermittent red flames. Both solutions bubble and hiss: the boric acid solution hisses when the flame is yellow; the strontium solution hisses all the way through.

Worse, I'm not having luck with sodium chloride or potassium chloride or cupric chloride.

Regarding NaCl and KCl, I can't really get either to dissolve in methanol. As a consequence, I just get the clear/blue methanol flame, not yellow nor purple. Anyone have any advice?

As for cupric chloride, I get a green flame, not the blue one from the video (starts out looking rather green, seems pretty blue after a little while).

 

[Dr_Morbius]

That's because NaCl and KCl don't dissolve in methanol. In fact none of the salts used in that video dissolve in methanol. What he did was that he dissolved them in water first then he added enough methanol so that the solution would ignite and sustain a flame.

Just dissolve the salts in water then add methanol. I'd recommend trying 75% methanol and 25% salt solution. If the colors aren't bright enough increase the ratio of the salt solution to methanol. You just need enough methanol to ignite the solution. It doesn't have to be methanol by the way; it can be isopropyl alcohol or ethanol. Any alcohol that mixes with water will suffice.

 

[vaselinessa]

Good to know. I'm trying what you suggested. Hit or miss so far.