Question

urn in only the Data, Post Lab Questions, and Conclusions for this experiment POST-LAB QUESTIONS: t. Why is it necessary to use a pencil instead of a pen when drawing the origin line and labeling the pltan ml nhe used Calculate the Rf (Retention factor) value for the spot on this chromatograph. Write formula and show set-up. 2. Solvent Compound Baseline Origin) ph below shows the sample separated into two spots (2.5 cm and 7.5 cm). The distance alues for both of the between the origin line and the top of the solvent front is 10.0 cm. Calculate the Rf v components in this mixture. Show the set-up for each calculation. Solvent Level 7.5 em Compounds of the Sample 10 cm 25 cm *-|Sample Spot Initial Solvent Level 4. In the example above, which spot (2.5 cm spot or 7.5 cm spot) is the component that is more strongly attracted to the -0H groups of the cellulose in the stationary phase (more polar)? Briefly explain your reasoning (Exp. 3, version 5) Page 6 of8

Answer 1

Ans 1 :

The chromatography paper splits up the mixture of compounds into its respective subparts.

Now if the pen is used on the paper, ink will be dissolved and the paper will seperate it into its compounds. This can interfere with the dyes used in the experiment and affect the results.

So it is necessary to use a pencil instead of pen when drawing the origin line and labelling the sample spots.