Part A: Sample Preparation

Question

Live plant material is used in the absorption analysis. Chlorophyll and other pigments are removed using the protocol provided below.
Materials (per team):
Balance
Coleus leaf
Mortar and pestle
30 mL of ethanol
35 mL syringe
100 mL beaker
Funnel lined with a coffee filter
Safety goggles
SAFETY
Wear goggles and aprons when working with chemicals.
Alcohol is volatile and flammable.
Avoid breathing in vapors of the reagents.
Procedure:
1. Prepare an extract of chlorophyll by weighing 0.3 grams of your leaf sample. Make sure the sample includes all of the different colors on the leaf. Tear the leaf section into small pieces and place the tissue in a mortar for grinding.
2. Add 10 mL of ethanol to the sample and grind with the pestle until only tiny specks of leaf tissue remain. Add an additional 20 mL of ethanol to the mortar.
3. Filter this liquid into a beaker through a funnel lined with a coffee filter.
4. Dispose of the filter in the designated trash bin.
use the above information and write a good procedure in a practical correctly

Answer 1

Procedure for Chlorophyll Extraction from Coleus Leaves

Objective

To prepare an extract of chlorophyll from Coleus leaves for subsequent analysis.

Materials Required (per team)

• Balance
• Coleus leaf
• Mortar and pestle
• 30 mL of ethanol
• 35 mL syringe
• 100 mL beaker
• Funnel lined with a coffee filter
• Safety goggles
• Apron

Safety Precautions

1. Wear protective gear: Always wear safety goggles and an apron when working with chemicals.
2. Handle ethanol with care: Ethanol is volatile and flammable. Ensure that you are working in a well-ventilated area and keep away from open flames.
3. Avoid inhalation: Do not breathe in vapors from the reagents; use the equipment responsibly.

Procedure

1. Weigh the Leaf Sample: Using the balance, weigh out 0.3 grams of the Coleus leaf. Ensure the sample includes a mix of the different colors present on the leaf.

2. Prepare the Mortar: Tear the leaf into small pieces and place them into the mortar. This will facilitate the grinding process.

3. Add Ethanol:

   • Measure 10 mL of ethanol using the syringe and pour it into the mortar with the leaf pieces.
   • Use the pestle to grind the mixture thoroughly until only tiny specks of leaf tissue remain visible in the liquid.

4. Add Additional Ethanol: After grinding, measure and add an additional 20 mL of ethanol to the mortar. Continue to grind the mixture to ensure maximum extraction of chlorophyll.

5. Filter the Extract:

   • Position the funnel lined with a coffee filter over the 100 mL beaker.
   • Carefully pour the liquid mixture from the mortar into the funnel, allowing the filtrate (the liquid) to collect in the beaker while the solid leaf debris is retained by the filter.

6. Dispose of the Filter: Once the filtration is complete, discard the used coffee filter containing the leaf tissue into the designated trash bin.

7. Final Steps: Make sure to label the beaker containing the chlorophyll extract properly. It is now ready for further analysis.

Notes

• Ensure that all steps are performed with precision to promote optimal extraction of pigments.
• Clean up the workspace after completing the procedure, ensuring that all materials are disposed of and equipment is returned to its proper place.

This procedure will yield a chlorophyll extract suitable for absorption analysis.