seperating mixtures

seperating mixtures

1. definitons

   • element
     •  An element is a pure chemical substance made of same type of atom.
   • mixtures
     • a mixture is a material made up of two or more different substances which are physically combined.
   • compounds
     • A compound is a substance formed when two or more chemical elements are chemically bonded together.

2. filtration

   • Filtration is a process used to separate solids from liquids or gases using a filter medium that allows the fluid to pass through but not the solid. 

3. crystalisation

   • Crystallization is the solidification of atoms or molecules into a highly structured form called a crystal.

4. distillation

   • simple
     • Simple distillation works because the dissolved solute has a much higher boiling point than the solvent. When the solution is heated, solvent vapour evaporates from the solution. The gas moves away and is cooled and condensed. The remaining solution becomes more concentrated in solute as the amount of solvent in it decreases.
   • fractional
     • Fractional distillation works because the different liquids have different boiling points. When the mixture is heated: vapours rise through a column which is hot at the bottom, and cold at the top vapours condense when they reach a part of the column that is below the temperature of their boiling pointthe liquid flows out of the column There are two ways of obtaining different liquids from the column: By collecting different liquids from different parts of the column. The substance with the lowest boiling point is collected at the top of the column.By continuing to heat the mixture to increase the temperatures in the column. The substance with the lowest boiling point is collected first. Different liquids can be obtained from different parts of the column, or by continuing to heat the mixture to increase the temperatures in the column.

5. chromatography

   • Chromatography is a laboratory technique for the separation of a mixture. The mixture is dissolved in a fluid called the mobile phase, which carries it through a structure holding another material called the stationary phase. The various constituents of the mixture travel at different speeds, causing them to separate. The separation is based on differential partitioning between the mobile and stationary phases. Subtle differences in a compound's partition coefficient result in differential retention on the stationary phase and thus affect the separation.