Seperation of Mixtures
Separation of a Mixture
Introduction:
Mixtures are not unique to chemistry; you use and consume them on a daily basis. The beverages you drink each morning, the fuel you use in your automobile, and the ground you walk on are mixtures. Very few materials that you encounter are pure. Any material made up of two or more substances that are not chemically combined is a mixture.
The isolation of pure components of a mixture requires the separation of one component from another. Techniques needed to do this separation take advantage of the differences in physical properties of the components. The techniques you will use in this lab include the following: 1. Sublimation. This involves heating a solid until it passes directly from the solid phase into the gaseous phase. The reverse process, when the vapor goes back to the solid phase is called deposition.
2. Extraction. This uses a solvent to selectively dissolve one component of the solid mixture. With this technique, a soluble solid can be separated from an insoluble solid.
3. Decantation. This separates a liquid from an insoluble solid by carefully pouring the liquid from the solid without disturbing the solid. 4. Filtration. This separates a solid from a liquid through the use of a porous material as a filter. Paper is a good filter. Filters allow the liquid to, pass through but not the solid.
5. Evaporation. This is the process of heating a mixture in order to drive off a volatile liquid and make the remaining component dry.
The mixture that will be separated in this lab contains three components: naphthalene, C10H8, common table salt, NaCl, and sand,
SiO2. The separation will be done according to the scheme shown on the next page and involves three basic steps:
1. Heating the mixture to sublime the naphthalene.
2. Dissolving the table salt with water to extract.
3. Evaporating water to recover dry NaCl and sand.2
Mixture: naphthalene,
NaCl heat to naphthalene
Introduction:
Mixtures are not unique to chemistry; you use and consume them on a daily basis. The beverages you drink each morning, the fuel you use in your automobile, and the ground you walk on are mixtures. Very few materials that you encounter are pure. Any material made up of two or more substances that are not chemically combined is a mixture.
The isolation of pure components of a mixture requires the separation of one component from another. Techniques needed to do this separation take advantage of the differences in physical properties of the components. The techniques you will use in this lab include the following: 1. Sublimation. This involves heating a solid until it passes directly from the solid phase into the gaseous phase. The reverse process, when the vapor goes back to the solid phase is called deposition.
2. Extraction. This uses a solvent to selectively dissolve one component of the solid mixture. With this technique, a soluble solid can be separated from an insoluble solid.
3. Decantation. This separates a liquid from an insoluble solid by carefully pouring the liquid from the solid without disturbing the solid. 4. Filtration. This separates a solid from a liquid through the use of a porous material as a filter. Paper is a good filter. Filters allow the liquid to, pass through but not the solid.
5. Evaporation. This is the process of heating a mixture in order to drive off a volatile liquid and make the remaining component dry.
The mixture that will be separated in this lab contains three components: naphthalene, C10H8, common table salt, NaCl, and sand,
SiO2. The separation will be done according to the scheme shown on the next page and involves three basic steps:
1. Heating the mixture to sublime the naphthalene.
2. Dissolving the table salt with water to extract.
3. Evaporating water to recover dry NaCl and sand.2
Mixture: naphthalene,
NaCl heat to naphthalene