Miscellaneous chemistry experiments
The typical non-metals have their own characteristic chemistry, which really is very different, when compared with typical metal chemistry. Especially the halogens and chalcogens have interesting chemical properties.
List of fully worked out experiments:
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Characteristics of an electrolysis cell. In this experiment, the relation between voltage across and current through an electrolysis cell is investigated. The relation appears to be approximately exponential in the applied voltage. |
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High voltage electrolysis
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Nice dendritic crystal structures. A solution of ammonium chromate is allowed to evaporate to dryness. The solution looses ammonia, and hence ammonium dichromate is formed. Very interesting fractal patterns are produced, with the yellow ammonium chromate having a rather different structure than the orange ammonium dichromate. |
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Red chemiluminiscence with chlorine swimming pool chemicals. Hydrogen peroxide (30%) is added to some solid swimming pool chemicals. This gives a clearly visible red chemiluminiscence. This experiment is particularly interesting, when done in a dark room. |
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Beautiful green fluorescence -- synthesis of fluorescein. Phtalic anhydride and resorcinol can be forced to react with each other in the presence of a strong dehydrating agent, such as concentrated sulphuric acid. The resulting compound shows very strong and beautiful fluorescence. This is a simple, but really beautiful experiment. |
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Reaction between calcium and water - heat of reaction. Calcium metal is added to water. Initially the reaction is not that violent, but in due time, it becomes more and more violent. |
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Electrolysis experiments with special effects at the cathode. Usually, the chemistry at the anode is most interesting in electrolysis experiments, while at the cathode just hydrogen is produced. This set of experiments demonstrates that with suitable chemicals there also can be interesting and colorful effects at the cathode. |
. The experiment,
described in this page is somewhat at the border of physics and
chemistry. A salt solution is electrolysed with a plasma beam as anode,
generated from a high voltage source, supplying an output voltage of
more than 10 kV.
Tidbits and raw material with some nice results and ideas:
- Beautiful effects with potassium dichromate and hydrogen peroxide. Small crystals of potassium dichromate are sprinkled on the surface of a very dilute acidified solution of hydrogen peroxide. The crystals remain floating on the surface, slowly releasing dichromate in solution. This reacts with the hydrogen peroxide and this gives beautiful effects
- Dangerous experiments with sodium metal. Some sodium metal is put in a test tube which contains some dilute hydrochloric acid. Hydrogen gas is produced in this reaction. The heat of the reaction is so great, that at a certain point, the hydrogen explodes with a loud bang.
- Violent reaction between nitromethane and sodium hydroxide. Sodium hydroxide is added to pure nitromethane. After a short induction period, a violent reaction occurs.
- Nice effects in petri dish with yellow precipitate. A small amount of potassium iodide is put in a petri dish, filled with water, and a small amount of lead nitrate is put in the petri dish at the other side. The compounds dissolve and slowly diffuse towards each other. When they reach each other, a yellow precipitate of lead(II)iodide is formed. The slow diffusion results in a nice effect.
- Violence of a nitration runaway. A nice and funny experiment. Some isopropyl alcohol is added to a mix of nitric acid and sulphuric acid. As soon as the alcohol reaches this mix, an exceedingly violent reaction occurs, in which a big plume of red/brown nitrogen dioxide is formed.
- Thionyl chloride and potassium dichromate. Potassium dichromate is dissolved in thionyl chloride and some sulphuric acid is added. This gives some chromyl chloride and a deep red solution. When this mix is added to water, then a violent, but rather spectacular and in some sense beautiful reaction starts, giving a cloud of HCl and chromyl chloride.
- Collapsing styrofoam. Some acetone is sprinkled on a piece of styrofoam (the white packing material, consisting of many small white bubbles). The styrofoam literally collapses when this is done. A funny experiment which does not require any special chemicals.
- Making 90% nitric acid. Standard nitric acid of approximately 60% concentration is further concentrated to 90%, using a distillation setup and concentrated sulphuric acid.
- Making pure bromine. Pure and dry bromine is made from potassium bromate, sodium bromide and sulphuric acid. A distillation setup is needed for isolating the bromine, and concentrated sulphuric acid is used to make the bromine perfectly dry. The potassium bromate in turn is made by electrolysis, described in another experiment.