Photosynthesis Test

Test Background

• This experiment focuses on the two products generated by photosynthesis: Starch and Oxygen.

Starch Test

R-DIN Test

• Test Objective: Detect the presence of starch in leaves.
• Reagents:
  • R-DIN Solution: Brown in color
  • Starch Solution: Mix water with starch
  • Changes:
    • A solution containing starch will change from brown to a deep blue-black
    • Distilled water without starch will remain brown

Leaf Starch Detection Steps

1. Boiling Water: Place the leaf in boiling water, turn on the Bunsen burner.
2. Alcohol Soak: Heat alcohol to remove chlorophyll.
3. Hot Water Soak: Remove alcohol residue to restore the leaf's softness.
4. Add R-DIN Solution: Observe color changes to determine the presence of starch.

Scientific Basis of Each Step

• Boiling Water: Breaks down the cell wall, promoting reagent penetration.
• Alcohol Soak: Removes chlorophyll to make color changes more visible.
• Hot Water Soak: Removes residual alcohol, preventing leaf fragility.

Oxygen Test

Oxygen Collection and Detection

• Equipment and Reagents:
  • Bottle: Containing water and Sodium Hydrogen Carbonate
  • Sodium Hydrogen Carbonate: Provides additional carbon dioxide.
• Experimental Steps:
  1. Place the plant in the bottle, seal, and expose to sunlight for several hours.
  2. Use a Glowing Splint at the bottle's mouth and observe its reigniting.

Experiment Conclusion

• Gas Identification: The glowing splint reignites, proving the gas in the bottle is oxygen.