Solubilidad. Mezcla homogénea o mezcla heterogénea
Enviado por qca_ • 14 de Febrero de 2019 • Apuntes • 1.254 Palabras (6 Páginas) • 710 Visitas
3. SOLUBILIDAD
La solubilidad es la cantidad máxima de soluto que se puede disolver en una cantidad dada de disolvente.
Algunas sustancias, como el agua y el alcohol, se pueden mezclar y crean una fase homogénea en cualquier proporción. Estas sustancias se llaman miscibles. Por otro lado, si dos sustancias no pueden mezclarse (como agua y aceite), se llaman inmiscibles.
La solubilidad depende principalmente de la temperatura y la presión:
- Presión: Solo afecta a los gases. La solubilidad de un gas es directamente proporcional a la presión
- Temperatura: En general, se puede decir que la solubilidad de los sólidos aumenta con la temperature (aunque no es una regla porque no siempre es así). En el caso de los gases, su solubilidad disminuye cuando aumenta la temperatura.
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4. SEPARATING MIXTURES
4.1. SEPARATION OF SUBSTANCES IN A HETEROGENEOUS MIXTURE
METHOD | BASED ON | SEPARATE |
Magnet separation [pic 5] | Difference in magnetic properties. Metal remains stuck to the magnet. | Metals and other substances. Example: iron and sand |
Sieving [pic 6] | Difference in size. The larger solid substance remains in the sieve and the small one passes through | Two solids Example: stones and sand |
Filtration [pic 7] | Difference in size. The solid substance remains on the filter and the liquid passes through | Insoluble solid and liquid. Example: sand and water |
Decantation [pic 8] | Difference in density. Two immiscible liquids are separated by the action of gravity. The denser one goes down and the less dense goes up. It is slow and cheap | Two immiscible liquids Example: water and oil |
Centrifugal process [pic 9] | Difference in density. Two substances are separated by the action of acceleration (much bigger than gravity). It is fast and expensive | Solids, solid and liquid and liquids. Example: water and clothes |
4.2. SEPARATION OF SUBSTANCES IN A HOMOGENEOUS MIXTURE
METHOD | BASED ON | SEPARATE |
Distillation [pic 10] | Difference in boiling point artificial heating of a solution. The most volatile liquid evaporates and the other liquid remains. Recovery of gas by cooling | Miscible liquids (or gases) Example: water and alcohol |
Crystallisation [pic 11] | Evaporation of the liquid natural warming (sun) of a solution. The liquid evaporates and the solid remains. It is slow and cheap. It does not destroy sensible substances | A solid and a liquid Example: water and salt |
Liquid extraction [pic 12] | Difference solubility in two immiscible solvents. Substances are not destroyed by heat, but it is more expensive than distillation. | Any substance dissolved in another Example: Iodine dissolved in water is extracted with CCl4 that is immiscible in water |
Paper chromatography[pic 13] | Difference in speed of the particles through a porous medium The mixture is passed through a porous medium and the substances are separated by their different speed | Any substance dissolved in another Example: separation of ink components |
TEMA 3: ACTIVIDADES
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