This post contains a collection of animated gifs and other pictures from experiments we have been doing recently.
First a heart made by putting copper foil into silver nitrate solution (copper is more reactive than silver and displaces silver ions from solution).
Next, heating a beaker of ice to water and steam.
Those are anti-bumping granules you can see at the bottom of the beaker in the boiling water.
Now for a rather pretty B/Z reaction we carried out recently.
Captured using time-lapse mode
Finally, the curious case of the colour of chromium (III) ions in water. And hence the title of this post ‘Blue ruby’.
When asked “How do you make a blue heart red?”
“With a torch and chromium (III) ions”, I said
Jim Clark, writing on Chemguide.co.uk notes that “The simplest ion that chromium forms in solution is the hexaaquachromium(III) ion – [Cr(H2O)6]3+.” He also goes onto say that “The hexaaquachromium(III) ion is a “difficult to describe” violet-blue-grey colour.”
Our AQA A’ level Chemistry describes [Cr(H2O)6]3+ as being ruby in colour, but our solution of chromium (III) chloride definitely looks blue to me.
That is, until one looks at it under torchlight (tungsten filament bulb), then
indeed it does appear a ruby colour.