how to show that plant release oxygen?
Answers
Answer:
Explanation:
Gather the necessary materials. To prove that oxygen is a by-product of photosynthesis, you can set up an experiment with an aquatic plant and capture the gas it emits in response to photosynthesis. You will also set up a control condition where the plant will not be exposed to light, preventing photosynthesis. To perform this experiment you will need the following items:[2]
8 sprigs of an elodea plant, an aquatic plant available at your local pet or garden store
2 large, clear containers
Sodium bicarbonate (baking soda), no more than 1 tablespoon
2 large funnels (must be small enough to fit inside the large container)
2 test tubes (must fit over the end of the funnel)
a light source: sunlight or at least a 40-watt bulb
dechlorinated tap water (chlorine in the water will kill the plant), enough to fill both containers about ¾ full
Gloves
Prepare the elodea plants. For each sprig, remove several leaves at the base of the stem and cut the end at an angle. Gently crush the end of the stem with your fingers.[3] You will use four sprigs for each experimental setup.
Make the sodium bicarbonate solution. Fill the large container about ¾ full of room temperature dechlorinated water and add a few spoonfuls of the baking soda. Stir the solution until it is fully dissolved. This bicarbonate solution will provide the elodea with the carbon dioxide it needs to use photosynthesis.
Place the elodea sprigs in the bottom of the container with the funnel inverted over them. Add four sprigs to the bottom of each container. Invert the funnel and place in the container so that it covers all of the sprigs of elodea and the end of the funnel points towards the top.
Make sure there is enough water so that the end of the funnel is still submerged. Add more room temperature water, if necessary.
Fill both test tubes with water. Either submerge the test tube in water until there are no bubbles left in the tube or simply fill the tube all the way to the top. It is crucial to the experiment that there is no air trapped anywhere in the test tube.
Invert the test tubes and place over the stems of each funnel. Hold your thumb over the top of the test tube, gently turn the test tube over and lower the end into the water. Remove your thumb and check for any bubbles in the tube. If there are bubbles, tilt the tube until the bubbles escape to the surface. When all bubbles are gone, set the test tube over the stalk of the glass funnel.[7]
Ensure that the setup is stable and the test tube sits snugly on top of the funnel.
At this stage there should be no air bubbles anywhere in either of the test tubes. If there is air, remove the test tube, refill with water, and try again.
Store one jar in direct light and one jar in darkness. For the jar in direct light, place it near a window or next to a lamp. For the jar in darkness, store it in a dark room or closet with no windows. Leave a note on the door that says “Do Not Open” so your family will know an experiment is in progress.
The jar stored in the darkness is the “control” for photosynthesis. Since we are trying to prove that photosynthesis produces the oxygen, we want to make sure that no oxygen is produced in the absence of light.
Leave both jars alone for at least 8, but up to 24 hrs.[8]
After just a few hours, you should start to see air bubbles appear in the test tube of the elodea in the light.