1. Liquid Nitrogen JerryHancock

2. What are the Risks? Density of Gases at STP (Standard Temperature Pressure): Nitrogen (N): 1.25 kg/m 3 Carbon Dioxide (CO 2 ): 1.97 kg/m 3 Oxygen (O): 1.42 kg/m 3

3. How Does Oxygen get effected Gases evacuating Oxygen

4. 6 th Grade Science Project Materials: Dry Ice (CO2), 0.5 kg Liquid Nitrogen(LN2),0.5 kg Water (H20), 1 Liter Enclosed Plexiglass Chamber Notebook and pencil Oxygen Monitor, with string attached (for lowering and raising) Containers to hold CO2,LN2, and H2O Ruler, Scale and Stopwatch

5. Purpose Purpose: The purpose of this experiment is to find out which gas, nitrogen or carbon dioxide (dry ice), evacuates oxygen the fastest.

6. Hypothosis we think that nitrogen will evacuate the most oxygen because it expands 694 times and for dry ice it’s 554.

7. Conslusion 1.We taped a ruler onto the side of an enclosed 15” x 15” x 22” plexiglass chamber with a lid. 2.We tied a string around an Oxygen monitor that was long enough to be able to raise and lower the monitor along the ruler. The normal oxygen percentage it recorded before the experiment was 21.0%. We weighed a 0.5 kg block of Dry Ice (CO2) and placed it in a plastic container. 3.We measured out ½ liter of cold tap water. 4.We placed the container with the Dry Ice in the plexiglass chamber and added the water, then quickly closed the lid with the oxygen monitor in place by the ruler. 5.We recorded the oxygen percentages every minute at intervals of 0”, 3”, 6”, 9”, and 12” until the percentage stopped changing.

8. Conclusion 6.Next, we measured out 0.5 kg of Liquid Nitrogen (LN2). 7.We measured out ½ liter of cold tap water. 8.We poured the Liquid Nitrogen into the plastic container, then added this to the plexiglass chamber and added the water, immediately closing the lid with the oxygen monitor in place by the ruler. 9.We recorded the oxygen percentages every minute at intervals of 0”, 3”, 6”, 9”, and 12” until the percentage stopped changing. 10.We changed the recorded information into a graph form to help display the results.

9. Conclusion Because Liquid Nitrogen is 206˚F colder than Dry Ice (which is Carbon Dioxide (CO2) in its solid form), it took longer for the dry ice to melt and release CO2, so it did not show as drastic a change in Oxygen levels as with the Liquid Nitrogen at the initial introduction of the gas. Nitrogen evacuated the oxygen very quickly but then rapidly dispersed because it mixes better with air as it is similar density with oxygen. Our hypothesis was that Nitrogen will evacuate the most oxygen because in its liquid form of LN2, it expands 694 times while Dry Ice expands 554 times to CO2. Our hypothesis was correct, as we found that Nitrogen evacuated more oxygen immediately,but in the end, because CO2 is more dense than Oxygen, it evacuated more Oxygen over a longer period of time.