A CIESE Collaborative Project

# Fall 2007 Student Reports

## Institut Technique Don Bosco - Bruxelles, brabant, Belgique

Our hypothesis was: the higher you live, the lower the boiling point is.
We are surprised that we don't have the value as the other class of our school. Perhaps there was deaght!!
The atmospheric pressure was certainly different .
If we could do that project again, we take information about the atmosperic pressure.
We all enjoyed that project very much.
Axel, Kévi, Nelson, Gary, Vasco and Clovis.

## Rocky River Middle School - Rocky River, Ohio, USA

Results for RRMS:

We were rather surprised that the water boiled at something less than 100 degrees Celsius! That is what we have always been taught in the books we read.

We also noticed that many of our same lab stations had different readings for the thermometers. We concluded that either they were read improperly or the groups forgot to adjust their readings.

So to begin with, we found some unexpected results. Then we looked at the online information and found that what we though was really bad information from our school, turned out to be actually good information.

We made some interesting graphs and had some fun with the project.

Thanks for having this available for kids.

J. Schneider

## Cedar Drive Middle School - Colts Neck, NJ

Grade 8 Science - Mr. Gatti's Classes

The data collected by all five of my classes seems to be consistent. The class averages for the boiling point all hover around 98 degrees Celsius. This appears to be accurate for our elevation of approximately 23 meters.
The data from all participating schools was graphed by all students in all of my classes. This was done as a team effort, to reduce the amount of work each student was required to do. Each independent variable being considered in this experiment was graphed on a separate graph. My students were then asked to look for correlations between each independent variable and boiling point (the dependent variable). Each class was asked to come to a consensus. All five classes agreed that elevation showed the closest correlation to boiling point. During class discussion of these results, it was determined that the differences in air pressure as elevation increases was the causative factor for the lowering of the boiling point.

## American School of Tampico - Tampico, Tamaulipas, Mexico

Before doing this project, most of us thought that room temperature would have the greatest effect on the boiling point of water, so we were surprised to see that it didn't happen that way. As we learned initially from obtaining our background information, elevation is the factor that determines what the boiling point of water will be. It was interesting to apply this to the fact that is takes longer to cook things by boiling in places with high elevation.

One other question that came up in our analysis is to find out what the boiling point would be in places that are lower than sea level, so we are planning to begin an investigation to see if anyone has boiled water inside a mine, for example, or find out where it could be tested.

Thank you very much for this opportunity of international collaboration,

## Al-Ghazaly Jr./Sr. High school - Teaneck, NJ, USA

As we expected, the boiling point was below 100 degrees because we are about 100 feet above sea level. Our hypothesis was that boiling point would be about 98 degrees. We were surprised to find our average boiling point to be about 95 degrees. This perplexed my classes. Upon some investigation, we found that our lab used enviro safe thermometers that use a biodegradable green dye. These thermometers consistently had boiling points of 93, 94 degrees. Some groups did use mercury thermometers. These groups had boiling point of 99 and 99.5 degrees celsius.

In retrospect, if we were to repeat the experiment I would have had all groups use mercury thermometers. I believe these are more quantitavily correct.

My students enjoyed trying to figure out why there was such a big variation. We look forward to participating in the future.

Sally Amer

## Centro Escolar Cedros - Mexico, Mexico City, Mexico

(Report edited for length.)

Introduction:

The boiling point of a liquid is the temperature at which the vapor pressure of the liquid equals the environmental pressure surrounding the liquid. A liquid in a vacuum environment has a lower boiling point than when the liquid is at atmospheric pressure. And a liquid in a high pressure environment has a higher boiling point than when the liquid is at atmospheric pressure. In other words, all liquids have an infinite number of boiling points.
The normal boiling point (also called the atmospheric boiling point or the atmospheric pressure boiling point) of a liquid is the especial case at which the vapor pressure of the liquid equals the ambient atmospheric pressure. At that temperature, the vapor pressure of the liquid becomes sufficient to overcome atmospheric pressure and lift the li quid to form bubbles inside the bulk of the liquid.
Liquid may change to a vapor at temperatures below their boiling points through the process of evaporation.

Hypothesis:

The student is going to determine if the boiling point of water changes with differing locations & room temperatures.

Data:

The average of the boiling point of three days is 93.3 ºC with 21.3 ºC in the room

Discussion:

While boiling water in the lab at different temperatures, we could realize a there was a randomly boiling point of the water, as well as that it took longer at boiling water.
According to the charts downloaded from the web about height and boiling point, we can notice that at higher latitude the boiling point is at less.
Related to room’s temperature & boiling point we have that at higher room’s temperature the boiling point is higher, within the maximum & minimum range gotten in the experiments.

Conclusion:

As we could see in this experiment in the lab , we got boiling point temperatures from 92.5 ºC to 95 ºC , the difference is 2.5 ºC that is normal in a thermometer error range. As a result we got an average of boiling point in Mexico City of 93.6 ºC.
Considering data from web, we conclude that at higher altitude is less the boiling point, and at higher room’s temperature boiling point is higher up to100 ºC, and this would be our next question going back to our experiment, the question is.
Why room’s higher temperature influences the boiling point?

## Red Bank Regional High School - Little Silver, New Jersey, USA

We conclude, after drawing three different graphs that, as the elevation increases, the boiling point decreases. The graphs that we drew were: a bar graph showing volume versus boiling point, a line graph showing room temperature versus boiling point, and last, a line graph, showing elevation versus boiling point. If you live in high mountains, the boiling point of water would be lower than at sea level. We also conclude that volume does not affect the boiling point because in our school each class used a different volume of water. Our teacher demonstrated heating water with a Bunsen burner, while both classes used hotplates. We saw that the heating device did not affect the boiling point.

We enjoyed this project because we used different tools; for example, Bunsen burner, hot plate, and thermometers. We had fun and discovered that the boiling point of water does change. Thank you for letting us participate in the International Boiling Point Project.

Danie l, Eduardo, Jesus, Yesenia, Fidel, Sofia, Avinady, Gloria, Griselda, Arturo, Osvaldo, Alvaro, Sandra E., Sandra R., Alba, Marlen, Isabel, Lilia, Andros, Alberto, Miguel, Agustin, Gabino

## North Putnam Middle School - Roachdale, IN, USA

It was interesting to note that the class was all in consensus that the volume of water would have the greatest affect on boiling point. I believe they thought that the more water in the container, the more time it took to reach boiling point. We previously discussed the densities of states of matter and students had a little background knowledge that molecules in a liquid have the ability to flow freely. We also had some discussion about atmospheric pressure changes as altitude changes, either increasing or decreasing.
The students were surprised to discover that they all did not have the same thermometer readings even though they were all using the same type of heating device, volume of water, and same type of thermometers. They soon discovered that perhaps their inaccuracies in reading the thermometer was a relevant factor in their data analysis. I think the interesting thing that they noticed was that the boiling point of water being always stated as 100 degrees Celsius was not so at their elevation. The class data showed boiling point to be less than 100 degrees at our elevation, which was only 259 meters.
The students graphed all the data and by using trendlines were able to determine that elevation had the greatest affect on the boiling point of water, with the boiling point being less as you increase altitude.
Overall the class enjoyed doing the experiment and realize the importance of keeping accurate data but analying all of the data from all of the schools was time consuming for them. However, the struggled through the graphing process and learned how to draw trendlines to see the correlation between independent and dependent variables.