Chemistry SIA 2007

Introduction
Backgrnd Info
Experiments
Conclusions
Bibliography

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CHEMISTRY SIA 2007;
311 Group

Thursday, May 3, 2007

The second experiment done:

The following experiment has proven that the liquid is not as reactive when it is left open for a few moments before putting in Mentos.

This proves that the dissolved carbon dioxide that is in the cans is one of the main “culprits” to this Mentos reaction. When the can is left in the open, the gas would be able to escape into the air and thus, lesser reaction with the Mentos will be formed.

Through this second experiment, the group would like to conclude that time would actually make a difference in the amount of reaction between coke and Mentos.

There might be similar reactions between fizzy drinks and our body, except that the reaction may not be as huge. Therefore, through this experiment, we feel that in the future, those who drink fizzy drinks would leave the can or bottle open and leave it for a short period of time before drinking – and as one can see, through the experiment, leaving the cans open for at least 1 minute before putting in Mentos (which in this case actually “simulates” the drinking of coke by a person) will allow lesser reaction between coke and Mentos.

We also feel “cheated” as the reactions between Mentos and coke, as seen from videos online, were impressive and humongous. However, the reactions for our experiments were measly and only shot up to a maximum of approximately 3 centimeters. This may be due to the method used to put in the Mentos – that is, to slot all the Mentos into a tube that allows Mentos to fall into the bottles smoothly, and thus, allowed the Mentos to all drop into the bottle of coke smoothly (once it is opened).

The group had also met with some unexpected results. After the experiment, when the group was about to clear up, we realized that there was a difference in the volume of the cans – the first can with 7 Mentos felt relatively lighter that the other cans.

This allowed the group to conclude that during the reactions, more coke was spurted out from the cans – in the form of huge bubbles and liquid.

After conducting both experiments, we got the results and the second experiment proved our hypothesis right. If we leave the can of coke exposed to the surroundings for a longer period of time, there is indeed lesser carbon dioxide as compared to the original coke.

updated{at}5:27 AM

Profile

Hanjing(#09) Sandy(#17) Sarah(#18)
Class: 311'2007
Website: www.ch-oke.blogspot.com

Introduction

The topic that our group will be doing is the chemical reaction between the Mentos and the coke.
We will be observing the different reactions of the coke when the Mentos is placed in at different times.
We decided to do on this topic is because we are curious to find out whether the difference in time when the Mentos is placed into the coke will affect the reaction.

Hypothesis

Our hypothesis is that a can of coke when exposed to the surroundings for a longer period of time, lesser carbon dioxide will be present in it.
We will put a Mentos immediately into one of the cans to serve as a control. This can of the coke will enable us to compare with the rest of the cans where the Mentos were put in at different times.

Background Information

The group researched on the net for relevant articles which were related to our topic in order to know more about the reaction between Mentos and Coke. In all, we found 3 articles and the websites can be found in our bibliography. The articles told us about two middle-aged men who were intrigued with the effect when they dropped Mentos into Coke bottles. They decided to research, testing various configurations and tried all sorts of sweets and drinks. This made us even more interested and curious to carry out this particular experiment to see for ourselves the results which the two men had found so intriguing. These articles also reminded us of how people can discover new reactions that are intriguing just by playing around with a can of coke and Mentos while bored. You do not need a scientist for these; we can discover them ourselves. The articles also revealed how a scientist at The University of Manchester would be taking up her own version of this Coke-Mentos reaction into schools to stir up interest in chemistry. The group thinks that this would be very helpful in creating more interest as now, the methods with which students are being taught chemistry is not very engaging and interesting. By using Coke and Mentos which these students are familiar with, there may be a chance that they will be more interested in chemistry.

Through these articles which the group had found, we learnt about the science behind the spewing caused by the reaction. This is because when mint Mentos are dropped into Coke, they set off a process that causes almost all the fizz to latch onto the microscopic nooks and crannies on the candy’s surface. It so happens that Mentos happens to have thousands of these tiny pits. When the mints are dropped to the bottom of the bottle, all that gas is released and the soda is blasted out of the bottle, which results in a cola geyser.

The group feels that the articles have been extremely helpful in assisting the way of how we plan our experiment and what to use. It enabled us to have a deeper understanding of how the reaction between Coke and Mentos worked, and taught us how to set up the experiment properly in order to ensure accurate results.

Reflections & Conclusions

We felt that this SIA really helped us to explore more about the world of Chemistry. In fact, we have realised that it is interesting and that we can learn much from researching online from different websites and studying different kinds of hypothesis and information. We also learnt much from each other, taking note of our strengths and weaknesses so that we could remember how to make use of them properly in future. We realised that it is important to work together as a group in order to complete the task on hand punctually.

After conducting the two experiments, we have found out that in fact, Coke is bad for us if we drink it almost immediately after opening the can. This is becasue there will be a larger amount of carbon dioxide which will enter our body. We should open it and leave it out for a few minutes before drinking as this can help to reduce the amount of carbon dioxide that we take in. We would like to thank Mr. Kuo for his invaluable guidance and support as well as one another for encouraging and constant pushing along this project.

There are areas for improvement as well. We could have managed our time better and not do things at the eleventh hour. We should have followed our time schedule written in the proposal and so we would not have to do things all at a go. A time schedule is made in a way such that the work load is evenly spreaded out and we should follow it accordingly.

Bibliography

http://www.npr.org/templates/story/story.php?storyId=5341058
http://news.yahoo.com/s/bw/20070116/bs_bw/tc20070116569213
http://biz.yahoo.com/bizwk/070116/tc20070116569213.html?.v=1
http://www.eepybird.com/science2.html
http://antoine.frostburg.edu/chem/senese/101/consumer/faq/mentos.shtml
http://www.manchester.ac.uk/aboutus/news/display/index.htm?id=84279
http://www.zap2it.com/tv/news/zap-mythbustersmentos,0,4325641.story
http://www.mercurynews.com/mld/mercurynews/news/local/states/california/the_valley/15323794.htm

Pictures on the website: www.deviantart.com