Photosynthesis

• Photosynthesis experiment


  1. Place test tube rack 10 cm away from light source

  2. Fill boiling tube with sodium hydrogen carbonate solution

  3. Place cut pondweed into boiling tube

  4. Leave to rest for 5 minutes

  5. Start stopwatch and count bubbles for 1 minute

  6. Repeat bubble count twice more and take mean

  7. Repeat for 3 more distances (20, 30, 40 cm)

  8. Plot graph of rate of photosynthesis vs light intensity
• Temperature may also be a factor affecting the rate of photosynthesis and this is not taken account of
• Bubbles may form too quickly to be counted