Question

analysis of part 1: paper chromatography

1. describe in detail what was happening with the leaf pulp/extract after the filter paper was placed in the solvent.
2. what is a solvent?
3. what was the solvent in this lab?

ether acetone solvent

1. what was the solvent doing in this lab?
2. why might your rf value be different from those listed in the chart?

Explanation:

1. After the filter paper with leaf pulp/extract was placed in the solvent, capillary action caused the solvent to move up the filter paper. As it moved, it carried the different pigments (components of the leaf extract) at different rates. This is because different pigments have different solubilities in the solvent and different affinities for the filter paper. Some pigments dissolve more readily in the solvent and are carried further up the paper, while others adhere more to the paper fibers and move more slowly.
2. A solvent is a substance that can dissolve other substances (solutes) to form a solution. It is usually the component of a solution that is present in the largest amount.
3. As per the given information, the solvent in this lab was ether - acetone solvent.
4. In this lab, the solvent was acting as the mobile phase in paper chromatography. Its main role was to carry the components (pigments) of the leaf extract up the filter paper. The differences in how the components interact with the solvent (solubility) and the stationary phase (filter paper) lead to their separation.
5. There could be several reasons for an Rf (Retention Factor) value to be different from those in the chart. Contamination of the sample or the solvent, differences in the type or quality of filter paper used, inaccuracies in measuring the distance the solvent front and the pigment traveled (e.g., human error in measurement, uneven drying of the chromatogram affecting measurement), or slight variations in the composition of the leaf extract (if leaves from different plants or different parts of the same plant were used) could all cause discrepancies.

Answer:

1. Solvent moved up filter paper by capillary action, carrying leaf extract pigments at different rates based on solubility and paper affinity.
2. A substance that dissolves solutes (usually in largest amount in a solution).
3. Ether - acetone solvent.
4. Acting as mobile phase to carry leaf extract components up filter paper for separation.
5. Contamination, filter - paper differences, measurement inaccuracies, or extract - composition variations.