Required Praticle: Photosynthesis

Question 1

Method:

Answer 1

1) Take a boiling tube + Placing it 10cm away from an LED light source.
2) Fill the boiling tube with sodium hyrogen carbonate solution. This releases co2 which is needed for photosynthesis.
3) Put a piece of pond weed into the boiling tube with the cut end at the bottom.
4) Leave for 5 minutes to acclimatise to the coniditions in the boiling tube.

Question 2

What can be seen?

Answer 2

• Bubbles of gass being produced from trhe cut end of the pond weed.
• This os oxygen.
• Start a stop watch and count number of bubbles produced in 1 minute.

Question 3

Final:

Answer 3

• Repeat two more times.
• Calulcate the mean number of bubbles produced in one minute.
• Do whole experiment again from the start at 20cm then 30 cm then 40 cm.

Question 4

Why is an LED light used?

Answer 4

• Does not release a lot of heat.

- Too much heat would change the temperature of the experiment.

Question 5

What happens if you have to use a normal light bulb\?

Answer 5

• Place a beaker of water between the light and boiling tube toabsorb the heat.

Question 6

What are the problems of this experiment?

Answer 6

• Bubbles may too fast to count.
• ## Bubbles are not always the same size a large buble will count as a same bubble.