PolarNonpolar solvents using chromatography Purpose To use paper

Polar/Nonpolar solvents using chromatography

Purpose • To use paper chromatography to observe separation of substances in different polar solvents.

Principles of Paper Chromatography • Capillary Action – the movement of liquid within the spaces of a porous material due to the forces of adhesion, cohesion, and surface tension. The liquid is able to move up the filter paper because its attraction to itself is stronger than the force of gravity. • Solubility – the degree to which a material (solute) dissolves into a solvent. Solutes dissolve into solvents that have similar properties. (Like dissolves like) This allows different solutes to be separated by different combinations of solvents. .

Preparing the Chromatography Strips • Get 2 rectangles of paper • Draw a line 1 cm above the bottom edge of the strip with the pencil • Make marks each 3 cm to • To

Choosing Substances • Pick 5 substance to test-each paper will have the same 5 substances – – Candy Markers Powders Food coloring • Pick 2 solvents

Adding the substances • Using a round stick – Dip into food color and touch to line – A drop of water on candy, dip and touch – Drop of water on powders, dip and touch – Use a dot from a marker Let dry and repeat again to make concentrated Label the dots

Preparing for separation • Fold into a cylinder and staple top and bottom

Developing the Chromatograms • Place cylinder in beaker (spots at bottom) containing about ½ cm of solvent (2 beakersdifferent solvents) • Make sure the solution does not come above your start line • Let strips develop until the ascending solution front is about 2 cm from the top of the strip • Remove the strips and let them dry

Analysis of Lab • FORMAL LAB REPORT