Silver fractals
Marzena Trybuszewska
Po raz pierwszy na łamach NO pojawiają się doświadczenia chemiczne! Dziś dość widowiskowa wersja procesu elektrolizy. Doświadczenie to możemy przygotować w szkole, lub w domu, jednak pamiętajmy, że wiele odczynników wymaga zarówno specjalnych warunków przechowywania jak i ostrożnego obchodzenia się z nimi.
1. Equipment
- Petri dish
- Pipette
- Watch glass
- Electrodes
- Baquette
- Weight spoon
- Spatula
2. Reagents
- AgNO3 - silver nitrate
- Clear water
- NH3 * H2O - Ammonia water (4%)
3. The experiment
- Prepare 1% solution of AgNO3
- Adding ammonia water to dissolve the precipitate
- Pour the results into petri dish. Connect the solution to the 13,5 voltage. Place positive electrode on the edge of the dish and negative electrode on the middle of the dish. The electrodes should only touch the surface of the solution
4. Observation
Silver fractals arise at the cathode - forming "structure trees". The structure is similar to fractal - "Barnsley fern"
5 Conclusions and explanations
- In the first step alkalisation AgNO3 by means of ammonia water precipitated Ag2O
- In the second step alkalisation precipitate soluble and created ion comperhensive Ag[(NH3)2]+
- It is electrolysis and produced is pure silver. There is production of silver in the beautiful shapes.
6 The possibility of teaching used in the classroom
During the explanation of electrolysis process and as an interesting interpretation of these processes.