Idea
The chemistry cubes presented here focus on the speciation of acid and base species, of elementary metals (Me°) and the corresponding metal-cations (Mex+) as well as of non-metals (O2°) and their anions (O2-). In addition the origin of the substances, phase transitions and solubility equilibriums of gases in water have been considered and are shown on the cubes in a way that the different turning options, that are possible, chemically make sense.
Acid and Base Cubes
Cube Nr 3: H2SO3
Cube Nr. 3: sulfurous acids H2SO3
Solid species of the acid and base cubes 1-9, if existing, are represented at the bottom of the cubes as well as the acidity constants, the pKa-values. Aqueous species are usually shown at the sides and gaseous species at the top of the cubes.
If solid or organically bound sulfur is combusted, sulfur dioxide gas is formed, which can first dissolve in water and then react with water to sulfurous acid. Depending on pH-value of the aqueous solution, sulfurous acid is beeing deprotonated to hydrogensulfite or sulfite, when pH-value is higher than pKa1 or pKa2, respectively.
Cube Nr. 3: H2SO3
The font on top of the cube allows only a turn in one direction. If you tip the cube backwards, the SO2-gas dissolves in water, where it reacts on to sulfurous acid (turn left).
If we turn on, the first acid and base couple can be seen at the same time.
The pKa1 values of sulfurous acid (acid 1) and hydrogensulfite (acid 2) can be found at the bottom of the cube, right below acid 1 and 2, respectively.
If we turn on, the second acid and base couple can be seen at the same time.
Metals and their Cations
Cube Nr. 12: Cu & Fe
The zero charge ° was added to the elementary metal in order to distinguish from the charges of the cations.
The slight change of the background color stands for always for an electron transfer.
Tipping the cube to the left, the metal is being oxidized:
Fe° --> Fe2+ --> Fe3+
Non-Metals and their Anions
Cube Nr. 14: S, O2, N2
The zero charge ° has also been added to the elementary non-metals to distinguish from the charges of their anions.
The slight change of the background color stands for always for an electron transfer.
Tipping the cube to the right, the non-metal is being reduced:
N3- <-- N2
Phase Transitions and Equilibria
Some phase transition processes and/or solubility equilibria, e.g. between the gas- and water phase, are shown on the cubes as well.
Left:
Equlibrium of solubility of carbon dioxide between the gas- and water phase (Henry's Law). The Henry constants KH are not given on the cubes.
Right:
Phase transitions such as the boiling or evaporation of liquid to gaseous water ("vapour"), or the condensation of gaseous to liquid water, are shown as well.
Contact
Markus T. Müller
Im Baumgarten 5
CH-8500 Frauenfeld
markus.mueller@kftg.ch
