sugar cube flame test

Discussion in 'Supporting Chemistry' started by Jade, Jul 11, 2019.

  1. has anyone tried this? I'm a little underwhelmed which makes me think I'm missing a trick.

    For me its no where near as good as the flame jars which is a pity because it looks really good in the pictures.

    Any suggestions for what i'm doing wrong?
  2. We have tried this, and yes online photos do look impressive, and we were also underwhelmed :(

    I don't think we are doing anything wrong, photoshop is to blame ;)
  3. fair enough, I'll stick to the trusty flame jars then!
  4. Ooh, whats that one?
  5. We use pyrex crystallising dishes, add a few spatulas of your metal salt and dampen with a few pipettes of ethanol and light. Keep some heat proof mats handy to put them out.

    Takes a bit of tweaking with the volume of ethanol, too much and you don't see any colour, too little and it doesn't burn for long enough, but they make a nice visually impressive demo at the start of the flame test lesson. The only one i have any trouble with is potassium, very hard to see the lilac.
    LAJ392 and stelden like this.
  6. I'll try that then, thanks :) We've done 'flame throwers' (salts dissolved in ethanol, in spray bottle, sprayed across a bunsen flame) but only with KS5. Quite similar, but yes, the potassium shows lilac only for a brief split second.
  7. We use a small ball of mineral wool soaked in a small amount of the metal salts made up in methanol. (only small amounts needed)
    maybe half a spatula or so of the salt and mix it with maybe 10-15ml of methanol.

    burn it on a double layer of tin lids and 2-3heat mats underneath though (it burns for some time and gets hot)
    but it does give a very good colour and burns for a decent amount of time too.

    demo only of course :p
  8. In a fume cupboard?