Mills,+Jennifer

Hydrofluoric Acid The reason that hydrofluoric acid is so dangerous is because it passes under your skin and reacts with chemicals. The fluorine from the hydrofluoric acid then attaches tot the calcium and the hydrogen attaches to important enzymes. Cells end up dying under the skin because the calcium, magnesium and enzymes are taken away from where they are needed. A successful way to counteract this was to boost calcium levels in the affected area by injecting it directly into an artery. A burn from hydrofluoric acid is unnoticeable at first, but can lead to severe problems and even death.

Greek Influences on Chemistry I found it very interesting that so many chemistry terms have Greek origins. I thought Argon’s name was very clever. It means 'no work,' or inactive, and it is a noble gas so it doesn’t react with other elements. I also thought it was neat how isotope means ‘same place’ and isotopes are found in the same place on the periodic table. Finally I learned that many of the numerical prefixes we use are Greek in origin. I knew what they meant, but I never knew they were Greek.

 Alternative Energy Sources I read the article called Drilling for Hot Rocks: Google Sinks Cash into Advanced Geothermal Technology. It talked about how one alternative energy source that we should be looking into is geothermal energy. I don’t really hear about this type of energy too much, because there hasn’t really been a lot of success with it yet. How it works is they drill down deep into the earth and break through all of the layers of rock. They then pump water down to a level where it can be heated by the heat from the earth’s core. The hot water is then brought up to the surface and turned into steam to turn turbines and be used for electricity. If this project could become a reality, it would really help produce a lot of reliable energy without the side effects of pollution. Jen, Some places in the world - Iceland for example- use almost exclusively geothermal power. MW

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It was very interesting to learn the science behind the track and field that I have used so many times for sports. I knew that the little turf beads were made of recycled rubber, but I didn’t know as much about the track. Vulcanization was a new topic for me to read about. I did wonder why the track has to be laid so specifically, being precut and having to degas for several weeks. Does it have something to do with the vulcanization process? I also wondered why they couldn’t use recycled rubber for the track if it’s ok for the turf. ======

Old vulcanized rubber becomes brittle over time. MW

Oil and Water This article was very interesting. I knew that oil and water did not mix, but I did not know it had anything to do with polarity. I of course knew water was polar, and very ‘sticky’ due to its hydrogen bonding, but I had never really thought about what the polarity of oil would be, but I learned it was non-polar. I also found it interesting how oil is actually hydrophobic. I had heard that oil was less dense than water, but I didn’t know whether or not that was really a contributing factor to their immiscibility.

Jen, OK. MW

Salt on Roads This article was very informative. I knew that the salt was put on the roads in the winter when they were icy, but I didn’t know specifically why. I never would have thought it had to do with lowering the freezing point. I also knew that it prevented more ice from forming, but I wasn’t really sure of the chemistry behind it. Having now learned how adding solvents to water can affect the freezing point, it seems like a very simple concept. It was also interesting to learn that in really cold places where this doesn’t work, they simply try to put something on the road to give traction. I don’t think I would want to drive on that. I liked how it explained why bridges freeze before roads because I have wondered about that before. Finally, I thought some of the new methods they are looking into were strange, like sugar cane and molasses. But whatever works I guess.

Jen, Yeah I guess. It seems odd that sugar and molasses would be cheap enough to out on roads? 5 stars. MW

Hand Warmers This article was very interesting to me because I have used these kinds of hand warmers before with varying degrees of success. One thing that stuck out to me was the fact that if too much oxygen gets into the package before your try to use it, or too much water gets out, it may not work as well. Because I have been stuck in cold temperatures hoping the hand warmers would actually warm up my hands, now I know that adding water will get the reaction going again. Prior to reading the article, I figured that some type of exothermic reaction had to be occuring to give off heat, but I didn't know what was reacting or how it got started. I also learned that depending on how they are made, they can last from 7 to 24 hours. I might need to get some of that kind because mine have never lasted that long. I think it would be interesting to see which type of absorbent material retained the most moisture before the reaction giving the best result.

Jen, OK. MW

Maple Syrup (mmmmm) As far as the chemistry of maple syrup goes, before reading this article the only things I really knew were that syrup was extremely viscous and that it was a sugar, so its composition was a carbohydrate chain. I knew that it came from tree sap, but not how it was really made. I really learned a lot from this article about the make-up of maple syrup and the chemical processes used to make it. For example, I didn’t know there were so many other minerals present in the sap, which become even more concentrated after the sap becomes syrup because after the evaporation process the entire syrup solution is much more concentrated than the sap was. I also learned that sap is acidic in nature, which I would not have guessed. Some other tie-ins to what we have learned that I found were thermo and solubility. It talked about how much heat was required to evaporate the water form the sap, and how heating the sap changed the solubility of some of the components of the sap, so afterwards some parts precipitated out to make what is called sugar sand. One other thing I noticed about this article was that it gave a temperature measurement using the Brix scale, which I had never heard of.

Jen, Well done! Very thorough. I take it you like maple syrup. :) 5 stars! MW

RUST!!! I always used to think that metal only rusted when it got wet, because that was the only connection I made first hand. Just this year I learned that it was actually due to a red-ox reaction. I didn’t know that it was considered electrochem though. This article kind of focused on why cars rust more in the Northern states than the Southern, the salt from the air in coastal areas speeds up the rust reaction by improving the conductibility of water. In the winter, salt gets in Northern water from being applied to the roads to help with ice. The article mentioned that making cars of gold and silver parts would cut down on rust problems (which made me laugh because the idea is preposterous), but they would not be ideal as far as cost and crash-stability go. The most practical thing to prevent rust is paint, which makes sense because I have noticed that cars that are all scratched up suffer from rust problems, as well as guard rails on the sides of roads. The paint separates the anode and the cathode, preventing the red-ox reaction from going.

Jen, Your early observations are correct - water is needed for rusting to occur. Imagine the rusting issues on off-shore drilling platforms! 5 stars! MW