formulate a hypothesis for this investigation of
to determine wether expired air contains
carbon dioxide. Apparatus are two beakers/
test tubes/straws,two drinking straws and
clear lime water
http://www.gcsescience.com/itestcarbondioxide.htm
please describe
Hypothesis: If expired air is passed through clear lime water in a closed system using beakers, test tubes, and two drinking straws, then the lime water will turn milky in color, indicating the presence of carbon dioxide in the expired air.
Hypothesis: In this investigation, it is hypothesized that expired air will contain carbon dioxide.
To conduct this investigation, the following steps can be followed:
1. Gather the apparatus: Get two beakers or test tubes, two drinking straws, and clear lime water. Ensure that all the equipment is clean and in good condition.
2. Prepare the clear lime water: Lime water is a common indicator used to detect the presence of carbon dioxide. To prepare it, mix calcium hydroxide (slaked lime) with distilled water until a saturated solution is obtained. This solution should be clear initially.
3. Set up the experiment: Take one beaker or test tube and fill it with the clear lime water. This will act as a control, showing the initial state of the lime water. Place the second beaker or test tube next to it, leaving it empty for now.
4. Connect the drinking straws: Take two drinking straws and connect them together end-to-end. This will serve as a pathway for the air to be blown.
5. Begin the experiment: Breathe out through the connected straws into the empty beaker or test tube. Try to blow as much air as you can into it. Repeat the process several times if necessary.
6. Observe changes: After blowing into the empty beaker or test tube, carefully insert the other end of the straw into the clear lime water, making sure it goes beneath the surface. Pay close attention to any changes that occur in the lime water.
7. Analyze the results: Observe if there is any cloudiness or change in color in the lime water. If carbon dioxide is present in the expired air, the lime water will turn cloudy or milky due to the formation of calcium carbonate, which is insoluble.
8. Draw conclusions: If the lime water turns cloudy or milky, it indicates the presence of carbon dioxide in the expired air. This confirms the hypothesis that expired air contains carbon dioxide.
Remember to keep all variables controlled throughout the experiment and repeat it multiple times to ensure accuracy.