2015‎ > ‎02‎ > ‎

Flame Tests

posted Oct 16, 2016, 11:21 PM by Grace Ong   [ updated Nov 22, 2016, 8:14 PM ]
The following post was first posted on Blogger on Tuesday, 3 February 2015.

Oh my! How the dust has settled on my blog after months of neglect!

The first blog of 2015 shall be a collection of photos of flame test demos which I gave my students when school started.

The Group 2 tutorial discussion was a notoriously boring one, so these demos were to 'light' things up a little. Sadly, only a handful of salts available in my school lab were suitable for the flame test!

Group 1

flame test for lithium ions (carmine red)                    flame test for potassium ions (lilac)

Group 2

flame test for calcium ions (brick red)                    flame test for barium ions (yellow green)

A Transition Element

flame test for copper(II) ions (blue green)

  1. I did not want to go through the hassle of cleaning a metal loop with concentrated hydrochloric acid, so I used disposable cotton swabs instead.
  2. Each cotton swab was soaked in de-ionised water before I coated it with a solid metal chloride.
    [Copper(II) sulfate was the only sulfate used; the other salts were chlorides.]
  3. The coated cotton swab was then introduced into the bunsen flame to produce the coloured flame.