jueves, 18 de febrero de 2010

FACTORES QUE AFECTAN A LA CRISTALIZACIÓN

Las siguientes fotografías de la práctica os ayudarán a elaborar el informe de resultados. Cuando os refiráis a una diapositiva indicad su número.
SIEMPRE LA IMAGEN DE LA IZQUIERDA SE REFIERE A DISOLUCIÓN EN FRÍO, LA CENTRAL A DISOLUCIÓN EN FRÍO SEMBRADA Y LA DERECHA A DISOLUCIÓN EN CALIENTE

Cristalizaciones en video

El autor de la primera cristalización, la del sulfato de cobre, nos describe el método..."These grew in about 4 hours, I put a host rock in the solution to have a nice display mount.
2 pounds of copper sulphate pentahydrate, $14. I got it at True Value Hardware, Root Killer is one of its purposes.
Heat 1 cup of bottled water almost to a boil. Put it in something that wont melt. Put 3/4 cup of the copper sulphate pentahydrate into the water and stir vigerously until the copper sulphate pentahydrate disolves. put a host rock in, perferably rough, NOT A SMOOTH ROCK, cover it up, set it aside and check it in about 8 hours. you will have crystals all around the inside of the cup and on the host rock. If you move the cup you may throw off the crystal growing process, so just peek. Wait 1 - 2 days for nice formations. "


Y sobre las condiciones de las otras cristalizaciones leer en... "Instructables"

Y respecto a la última donde aparecen tolvas de sal...
"Dr. Pettit grew salt crystals in stretched films of water so that the salt water only fed the crystals around the edges rather than from all sides, as happens in a glass of water. This video of his demonstration shows that surface tension plays a surprisingly dominant role in the crystal formation and convection is more active that one might expect. "