A CIESE Collaborative Project

# Fall 2000 Student Reports

## Conner Middle School

#### Hebron, Kentucky, USA

We are eighth graders at Conner Middle School in Hebron, Kentucky. From this international science project, we learned many new techniques and computer programs that can help us on future projects. We used a program, Microsoft Excel, to create a spreadsheet of the data collected in our school. From the spreadsheet we created graphs to compare boiling point to room temperature, volume of water, and elevation. Our hypothesis varied for each person. Two hypothesis that we randomly chose are: if the elevation is increased, then the boiling point will be greater, and if the volume of water is decreased, then the boiling point will increase.

The average boiling point for the 56 students was 100.5*C. Elevation was the factor in the experiment that showed the strongest correlation to boiling point. The proof we have to back up our answer is because according to the graph we created, the boiling point vs. elevation was the only one to show a correlation, negative. Also as you get higher in elevation, the air gets thinner and the air pressure decreases. So the heat trying to escape the liquid does not stay in bubbles on the bottom of the container it immediately rises to the surface to release the gas inside. As a result, the boiling point will be less, because less heat is needed to form a gas.

We were surprised at our results, because some of us did not know what would happen and had other ideas. The other class arrived at the same conclusion, and they had the same results. The results from other schools were the same as ours; many of them were surprised at their findings.

Picking a different location, such as Orlando, Florida, the predicted boiling point is probably about 100*C. Because the elevation is lower than ours and the lowest elevation is at sea level, it would have to be very close to 100*C, sea level boiling point, and less than ours.

Accuracy of measurements is very important in this experiment. The reason for this is because the boiling point could turn out wrong by following the directions wrong. Possibilities for inaccurate measurements are using a different burner, the amount of water is changed, the way the thermometer is read, if the thermometer is calibrated or not, and if there is metal holding up the thermometer or not. In our experiment, there could have been inaccurate measurements. One way to over come this is to have the same person do the experiment or the same job each day.

If we could change the experiment, we might have four people doing everything the same but on their own burner. Also keep those same four people on the same burner doing the experiment on each of the three days.

One variable we could test to see how it might affect boiling point is the different substances put in water. Examples of substances you could use are sugar in water, vinegar in water, and salt in water. Our hypothesis: If the salt is increased in amount in the water, then the boiling point will decrease. We learned many new strategies and techniques for future projects. This project was an incredible experience.

Conner Middle School Pintos

## Berkeley Preparatory School

#### Tampa, Florida, USA

After reviewing our data analysis, we came to the conclusion that, of the four variables investigated, elevation plays the most crucial role in the boiling point of water. We had hypothesized this as our outcome, since elevation is inversely proportional to atmospheric pressure and higher elevations should have less air pressure counteracting the vapor pressure of the liquid. From the data we were given, the graph "Boiling Point vs. Elevation" clearly shows the greatest organization of points, many of which fall along a straight line.

In the future we would like to see better controls on possible sources of error. These would include a two-point thermometer calibration (another temperature point in addition to water's freezing point), as we felt our thermometers were not all necessarily accurate. On our end, we felt it important to ensure that the atmospheric pressure itself did not change drastically, due to weather conditions.

We enjoyed the opportunity to take part in this experiment.

## Westhouse School

#### Birmingham, United Kingdom

Here in Birmingham, England our year 5 & 6 children have had great fun looking at our results and trying to suggest reasons for the fact that our water boiled above the normal boiling point when it should have been lower because we are 150 metres above sea level. We came to the conclusion that either our thermometers are not very accurate even though we did the calibration, or that the temperature on the days we did the experiments, did not take into account the influence of air pressure.Some even wondered if North Sea gas had any influence! We wondered if the American temperatures was recorded at a time when the barometer readings would have been different,from those in another location on the globe.As we drew our graphs the relation between height above sea level and a lower boiling point became evident, and this was a fascinating discovery. Thanks for the opportunity to contribute.

## Tigerton Middle School

#### Tigerton, Wisconsin, USA

This is Tigerton Middle School's final report. Our conclusion is that elevation affects the boiling point of water. Elevation affects the boiling point because if you are higher than sea level there is less air pressure meaning that water will boil at a lower temperature. If you are lower than sea level there is more pressure and water will boil at a higher temperature. Which means at sea level water should boil at 100 degrees Celsius. Boiling point is not affected by room temperature or the volume of the liquid. It would be interesting doing this experiment with different liquids.

This is the final report from Tigerton Middle School.

## Vernon Township High School

#### Vernon, New Jersey, USA

In the beginning my students discussed the possibilities concerning the effects of elevation, room temp., Volume of water boiled, and heating device used on the boiling point of water. After much debate, a bit of fist throwing and taking some bets... we hypothesized that the boiling point of water is most likely affected by elevation. However there was continued debate as to whether or not the boiling point increased or decreased as the elevation rose. A few students hypothesized that the boiling point was affected by the volume of water boiled. We graphed our data using Excel and analysed the data for a correlation between the boiling point of water and any of the variables. The r values showed that there was almost no correlation between the room temperature and the boiling point (r=.269), nor was there a correlation between the volume of water boiled and the boiling point (r=.219). However there appeared to be a correlation between the elevation and the boiling point. This surprised some of the students. We were also surprised to note how inaccurate our thermometers were. The only thermometers that measured with accuracy and precision were our few mercury thermometers. As a suggestion for future projects of this nature we might benefit from analyzing the accuracy and precision of the data obtained using different thermometers. Thank you for providing us with a means of sharing data with other schools around the world.

P.S. The BP of water DID turn out to be inversely proportional to the elevation - just like the textbook said!

## Weehawken High School

#### Weehawken, New Jersey, USA

Many of us formed different hypotheses during this experiment. Room temperature, heating devices, volume of water as well as elevation were all considered to affect the boiling point of water. We did discover, however, that it is only the elevation of the water's location that truely affects the boiling point the most. We think this happens because there is less oxygen (air) at higher elevations. Thank you for helping us learn this important fact and for giving us the opportunity to work with other schools!

## Jose Marti Middle School

#### Miami, Florida, USA

Hypothesis

The elevation will be the factor to have the greater influence in the boiling point of water. The reason for this is lower atmospheric pressure with greater elevations.

Results

We carefully selected the data in order to keep the variables constant. For example, to make the graph of the boiling point vs. average room temperature, we tried selecting schools with the same volume of water, the same range of elevation (0- 250m),and the same heating device. However, it was difficult to find enough data values that meet the standard . Therefore, we had to expand the ranges for some of them in order to get more values.

According to our analysis, the factor with the greater influence in the boiling point of water was the elevation. Comparisons of the lower half data average and the upper half data average were done in order to come up with this conclusion.

What We Have Learned

This was a magnificent learning experience. Probably the most relevant part was to understand the importance of changing one variable at a time. We have learned so much ! Thank you , thank you, very much! This was very exciting!

1. How to calibrate a thermometer. 2. Using internet data to determine elevations. 3. Understanding heat of vaporization and boiling point of water. 4. Understanding why the elevation influences the boiling point of water. 5. Analyzing and interpreting data. 6. Drawing conclusions.

Mrs. Flores's 7th Grade- Science Class

## Mt. Hope High School

#### Bristol, Rhode Island, USA

Period 2 Class

It is said that the standard boiling point (the point when a substance changes from a liquid to a gas) of water is 100°C (212°F). This science class produced results, stating that the average boiling point at 23 meters above sea level is 102.3°C. The purpose of this experiment was to answer the question Does elevation affect the boiling point of water? The answer to this question is yes, but this science class went over and above the useless one word answer. The groups hypothesis stated that the higher the elevation the higher the boiling point, which was wrong, but this triggered curiosity in the classroom! So why does the boiling point fall when at a higher elevation? This is because the higher the elevation, the less air pressure there is. The less air pressure there is means the air molecules are spread out more. This allows the water to perform a phase change faster than if the boiling water was at a lower elevation. A phase change is when a substance changes to a gas, liquid, or solid. The data (a collection of information) for this experiment was easy to get and produce. The charts and graphs were also very obvious that neither the room temperature nor the volume of water affected the boiling point of the water, unlike the elevation that affected it greatly.

Period 3 Class

The purpose is Does elevation affect the boiling point of water? Well it does. Our groups hypothesis was that the boiling point of water at a higher elevation will have a higher boiling point. This hypothesis was incorrect because the boiling point decrases at a higher boiling point because as the elevation gets higher and higher you have less air pressure. Our elevation is 23 meters above sea level and our average boiling point was 102.8°C. Also our room temperature did not effect the boiling point, 20.3° which was our average room temperature. We have learned when you are closer to sea level your air pressure will be pretty more air pressure then at a higher elevation. This means your boiling point will increase by more degrees then a higher elevation.

## Butler Catholic School

#### Butler, Pennsylvania, USA

After analyzing the data from this project, we, the 8th grade Beta group Science class from Butler Catholic School in Butler, PA, USA, have decided that elevation was the prime factor affecting the boiling point of water. We discussed our hypotheses and debated over whether or not impurities in the water (from dirty beakers etc.) may have also contributed. However, after much discussion and analyzing, we feel that elevation is the main factor. After we analyzed our data, we discussed our conclusion and then tried to think about why elevation affects boiling point. Our conclusion is that because the air has less pressure at a high elevation, then the water molecules can move around more easliy and it doesn't take as much energy (in the form of heat) for them to change over to a gas. This is opposite for water at low elevations.

## Wilson Middle School

#### Albuquerque, New Mexico, USA

Students plotted the elevation data and the boiling point data. They noted that a majority of the data points were made at elevations close to sea level and that there was a lot of scatter in the data. Once the data points were plotted, students drew a best fit line through the temperature data. Starting from 100 degrees Centigrade, they drew a straight line with about half the points above the line and about the other half below the line. Students noted that boiling point decreased as elevation increased and that the measurement made at our school, which is at a mile above sea level, fell right on the line.

## Jane Addams Junior High School

#### Schaumburg, Illinois, USA

Boil, Boil, Toil and Trouble Final Report 2000 - 2001

There are many variables that could effect the boiling point of water. For our experiment, we tested three of them.

The first variable we tested was the room temperature during the experiment. When we graphed our results for this variable, we found that the boiling points were scattered around the grid. We found no correlation.

The second variable we tested was the volume of water. Once again, we found that the boiling point had no apparent connection to this variable.

The last variable was elevation. When we graphed our results, we found that the higher the elevation, the lower the boiling point. We were surprised at this because our hypothesis was that there would be no change in the boiling point.

We also found that accuracy is very important. If our measurements are inaccurate it could affect the results of all the other schools participating in the study. We used laptop computers with probes attached. We feel we controlled all the variables and gave accurate results.

If we could do the project again, we would like to see if there is any correlation between boiling point and air pressure.

We think this project was very interesting because it shows how schools from all over the world can share information. This project also showed us why we need to be careful with our experiments and control as many variables as possible.

## Manalapan High School

#### Manalapan, New Jersey, USA

This project was brought to our statistics class and as aspiring students, we wished to meet the challenge of this project. We have completed an analysis of the data presented to us. Here is the link to the site containing the analysis:

http://se_stat.tripod.com/boilsite

## Long Branch Middle School

#### Long Branch, New Jersey, USA

We have learned much from completing this project such as the importance of following direction, how to read and calibrate a thermometer, and how air pressure affects the boiling point. No matter how long we boiled the water, it only would get to a certain height of temperature. No matter how long we stirred the thermometer in the ice water, it only would get to a certain low temperature. This gave us the boiling point and freezing point of the water. There is a certain amount of energy to change water from a liquid to a gas or solid.

We learned how to make and read the different types of graphs. Using Microsoft Excel, we made bar and line graphs of all the data given by the different schools, for each of the 4 factors. A graph is a visual display of information or data and showed us how to determine the most influential factor of this experiment. We used a bar graph to show the different types of heating devices and volume of water, and found that with each heating device or volume of water, there were many different boiling points. A line graph showed us that there were many boiling points for the same room temperature. A "line of best fit", drawn on a line graph of all the schools data, showed us how the elevation effects the boiling point temperature. It showed us that the higher the elevation the lower the boiling point, and the lower the elevation the higher the boiling point. This is because at higher elevation, there is less weight on the water because of lower air pressure. At lower elevations, there is more weight on the water because of higher air pressure or more air pushing down on the water.

The average boiling point for 3 different classes and 10 different groups in our school was 99.6°C. Our elevation is approximately 8.8 meters. We did take into account that we are on the second floor of the building. We learned how to find all of this information on different Internet sites. We are hoping that we will get more computers hooked up to the Internet so that we can use this type of information more often. We are not allowed to use the teacher station for security reasons.

There were many different hypotheses among the different groups. Some of the groups thought is was the heating device, one group thought it was the volume of water, and one group thought it was room temperature. The experimental results did support our hypothesis, which was elevation. The reason we picked this hypothesis was because of our discussion of the different air pressures at different elevations. We read the background information from the Boil, Boil website.

This summary is a composite of many group summaries. The students who participated in writing the summary are listed below. Our project is displayed on the bulletin board outside our classroom. We hope to include our pictures on the website soon. The project was a lot of fun. Thank you for allowing us to participate.

Cameron, Murilo, Lester, Barry, Araceli, Marlene, Marilia, Nicolette, Edna, April, Shameera, and Shakoora.

## Manalapan-Englishtown Middle School

#### Englishtown, New Jersey, USA

We would like to say that we enjoyed taking part in the Boiling Point Project. We learned many different things about the Boiling Point of water. Our class had several groups doing the experiment with the same volume, elevation, room temperature, and heating device and even though the boiling point was the same, the time it took each group to get the boiling point differed.

In our initial hypothesis we assumed room temperature would have an effect on the boiling point of water. However, after analyzing the data we found that elevation had the greatest effect on the Boiling Point. We graphed the results on a scatter plot graph to compare elevation, volume, and room temperature to the Boiling Point and compared the heating devices with a bar graph using the Excel program. It was obvious that there was a direct relationship between elevation and boiling point.

We felt that it is very important to control the factors in the experiment in order to be able to make a comparison. If the units of measure vary, the results will also vary and the comparison will not be accurate. Some possibilities for error might occur in timing the experiment or and inaccurate elevation reading.

If we could repeat the experiment we would like to see the volume of water be exactly the same amount for everyone. We would also like to use water from different sources to see if the boiling point differs from the boiling point of distilled water. Also, does the initial temperature of the water have an effect on the boiling point?

We are looking foward to other projects in the future. This project proved to be an enjoyable learning experience for everyone who was involved.