Water of crystallization
To show the presence of water in a coordination complex, not as an impurity but as part of the structure of the crystals.
Lo que aprenden los alumnos
La base científica de este experimento
Copper ions coordinate easily with water molecules to form coloured crystals or solutions. There is a marked difference in colour between anhydrous copper sulphate and the hydrate. This experiment shows the presence of water in the coordination complex.
Heating hydrated copper sulphate, CuSO4•5H2O, drives off the water coordinated with the copper ions.
Equipo utilizado
- Test tubes — 1473.60
- Test tube rack — 1680.06
- Test tube holder — 5423.30
- Spatula — 5460.34
- Spirit burner — 5514.10
Productos químicos y reactivos
- Copper sulphate — R:22-35/38-50/53 S:22-60-61
Notas de seguridad
- Take care when working with the burner and hot glassware.
Preguntas para los alumnos
- Record your observations.
Qué puedes esperar
<p>Some water vapour condenses on the upper part of the test tube, confirming the presence of water in the compound. The blue copper sulphate becomes dirty white in colour, showing that the water is not an impurity in the crystals but that a change in the chemical composition of the substance has occurred.</p><p>On adding a few drops of distilled water, the anhydrous copper sulphate becomes blue again showing that the hydrate has reformed.</p>
Eliminación
Dissolve the copper sulphate in water and dispose into the liquid wastes container.
Realiza este experimento en tu clase
Este experimento forma parte del « Mobile Lab » de ATP, un laboratorio autónomo que convierte un aula normal en un laboratorio de ciencias en pleno funcionamiento, con más de 200 experimentos de física, química, biología, robótica e ingeniería. « Gali », el tutor de IA integrado en ATP Connect, guía a los alumnos paso a paso y responde a sus preguntas en la mesa de trabajo.
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