First conceived and materialised ten years ago, The chemical domino 2017 consists of a series of captivating chemical reactions that follow in sequence in a Rube Goldberg type apparatus. The demonstrator only initiates the first reaction; the others follow in a cascade as a result of generating gases providing the necessary pressure to push solutions into reaction vessels which siphon into others and so on. Hence, creating a ''domino effect’’.
The reactions include:
1- Reduction of water by an active metal generating hydrogen
2- Acid-base neutralization reactions in solution monitored by
two pH indicators with production of carbon dioxide
3- Displacement (REDOX) reaction: reduction of metallic ions by
a metal of greater activity.
4- Formation of a coordination compound (transition metal
complex) with different ligands.
5- Decomposition of hydrogen peroxide by a copper (II) complex
6- Ligand substitution reactions of nickel (II) complex ion.
7- Pyrotechnic reduction-oxidation reaction between an alcohol
and an oxidising agent followed by the ignition of a fuel-
oxidising agent mixture.
8- Combustion of a cellulose nitrate string finishing with the
explosion of a hydrogen-filled balloon.
The chemical domino includes and covers many topics in chemistry and physics. It can be used as a review at the end of the academic year or set as a challenge to investigate the reaction mechanisms and classify the types of reactions. Moreover, it proves to be a good starting point for discussions and predictions based on the initial set-up.
Inspired and based on the article written by M. Dale Alexander in the Journal of Chemical Education, Vol.75, No. 4, April 1998.