Question 4
**Experiment 4: Solvents and leaf pigments**
1. Design an experiment showing that chromatography results are influenced by the type of solvent.
2. Draw the design on the answer sheet and carry out the experiment using the red and green “spinach” leaves.
3. Scrape the leaf surfaces to release pigments, using a coin if necessary. Identify every pigment found in the leaves. Allow approximately 15 minutes for results.
4. Calculate their $R_f$ values and record the results on the answer sheet.
5. When finished, place the paper results into plastic bags and label them correctly. Make sure the papers are dry before bagging.
6. Answer from your experiment:
a) Which solvent is better for leaf chromatography?
b) Is the pigment order similar for different leaves?
c) Write the pigment order for each leaf, beginning at the bottom of the paper immersed in solvent.
d) Do the same colors from different leaves have the same $R_f$ values? Write the $R_f$ for every pigment.
Use the materials and safety notes from Experiment 1, especially the precautions for 70% alcohol. The original source does not identify the plant species.
1. Design an experiment showing that chromatography results are influenced by the type of solvent.
2. Draw the design on the answer sheet and carry out the experiment using the red and green “spinach” leaves.
3. Scrape the leaf surfaces to release pigments, using a coin if necessary. Identify every pigment found in the leaves. Allow approximately 15 minutes for results.
4. Calculate their $R_f$ values and record the results on the answer sheet.
5. When finished, place the paper results into plastic bags and label them correctly. Make sure the papers are dry before bagging.
6. Answer from your experiment:
a) Which solvent is better for leaf chromatography?
b) Is the pigment order similar for different leaves?
c) Write the pigment order for each leaf, beginning at the bottom of the paper immersed in solvent.
d) Do the same colors from different leaves have the same $R_f$ values? Write the $R_f$ for every pigment.
Use the materials and safety notes from Experiment 1, especially the precautions for 70% alcohol. The original source does not identify the plant species.