More fun with luminol

We recently carried out a reaction with luminol dissolved in sucrose solution.

Luminol reaction in a measuring cylinder

Luminol reaction in a measuring cylinder


The idea was that by dissolving the luminol reaction mixture in a concentrated sucrose solution we could carry it out in the bottom of a measuring cylinder and ‘float’ a solution containing copper (II) ions and iron (II) ions above it. The experiment worked quite well and a short movie clip can be viewed here.
After a few seconds

After a few seconds

The details of how we carried out the experiment are shown below
How we did it

How we did it

Take care, by the time its all over it can get fairly messy as the images show below.
Lights on, lights off

Lights on, lights off

Almost over

Almost over

Another fine mess...

Another fine mess…


Here’s an image of our first experiment done on a smaller scale (approximately one tenth) using 0.025g luminol and in a 20ml measuring cylinder.
On a smaller scale

On a smaller scale


Thanks to Chris Kruger and Jonathan Barton in developing this experiment.

We hope you have fun with luminol too!

Answers to the “Bicarb rockets” questions last time:
1. sodium hydrogen carbonate + ethanoic acid -> sodium ethanoate + water + carbon dioxide
NaHCO3 + CH3COOH -> CH3COONa + H2O + CO2

2. f = ma
The carbon dioxide produced by the chemical reaction builds up inside the bottle and when the bung finally comes out the gas pressure forces the liquid out of the bottle quickly. It is the force of the liquid moving downwards which pushes the bottle upwards.