Kwon,+Sue

I learned that the tissues of the body contain chemical partners that fluoride is attracted to. Since the hydrofluoric acid does not carry a charge, it can easily pass through the fatty surfaces of membranes and the stratum corneum. I also learned that the fluoride and hydrgen ions break free of each other. When this occurs, fluoride attaches to calcium or magnesium which causes nerve failure and cell membranes to collapse. The hydrogen ion binds to enzymes that neutralize acids. Both of these reactions cause a disruption in the chemical balance in the body, which kills cells underneath the skin. Finally, I learned that the tissue damage occurs because the hydrofluoric acid causes very low levels of calcium. One way to treat a hydrofluoric burn is to inject calcium into the vein or radial artery.
 * Hydrofluoric Acid**

I learned and thought it was interesting that many of the terms used in chemistry were Greek-derived words. For example chroma- means color, I can relate that to chromatography which is used to separate pigments. It was interesting that the prefixes used to name binary molecular compounds (mono-, di-, tri-, tetra-, penta-, hexa-, hepta-, and octa-) were all derived from Greek numbers except nona- which comes from Latin. It is understandable though since the greek word for nine is ennea, which would be tough to use. Lastly, I thought the table with the etymologies of the chemical elements with their greek-derived names was the most interesting. I noticed that many of them were named after the color or smell of the element such as chlorine, chromium, bromine, rhodium, iodine, and osmium.
 * Influences of Ancient Greek on Chemical Terminolog****y**

Great job Sue!!! MW

I read the article on the nation's first solar-hydrogen house built by Strizki. The house runs on photovoltaic (PV) panels, which turn sunlight into electricity that is harnessed in turn to extract hydrogen from tap water.On a sunny day as much as 90 kilowatt-hours of electricity can be harvested. I thought it was really neat that the civil engineer produces all the fuel he needs right in his own garage. Although it was a costly purchase( $500,000) to construct, it is nice that he never has to pay a electric,oil, or gas bill again. His home-energy systems consists of 56 solar panels on his garage roof and a small electrolyzer inside. I learned that an electrolyzer is a device that uses electricity to break down water into hydrogen and oxygen. The oxygen is vented and the hydrogen gas is stored in propane tanks, in his backyard, which are used during the winter. The hydrogen is then run through fuel cell stacks which power his entire house, and the only waste product is water. He also stores energy in batteries, which powers the house in the night. Hopefully in the future many more peoples houses will run by solar hydrogen energy.
 * Alternative Energy Sources



The 56 solar panels on his garage

The electrolyzer

http://www.scientificamerican.com/article.cfm?id=hydrogen-house **

"Polymers in the Field"
 * Whenever I watched the olympics on T.V, I wondered how they could make sure that the lane lines and markers were equally placed out. I learned that there are embedded metal plates under the field in specific locations that allow the surveyors to accurately place the lane lines and markers on the track. After reading that they spray the turf with water, which lowers the temperature of the turf and that the higher heat capacity of the water makes the system more resistant to temperature change, reminded me of our thermochemistry unit. The turf cools quickly after the water is sprayed because thermal energy is transferred from a region of high temperature to a region of lower temperature. The fact that the turf would be more resistant to temperature change reminded me of the balloon demonstration that was done in class. When the water-filled balloon was placed above a lighter, the balloon did not pop because of the high heat capacity of the water. The balloon did not pop because the water absorbed the heat which did not allow the rubber to heat up enough to pop the balloon. Since water has such a high specific, it takes a lot of heat to raise the temperature . Just like the turf, this can also be related to the earth where extreme temperature changes are rare, since the majority of the earth is made up of water.

Awesome observations Sue!!! You write very well. MW**


 * Oil and Water**

After reading just the first paragraph, a couple thoughts came to my mind. First, I already knew that water was polar and oil was non-polar. I also knew that objects and substances with densities less than one, floated on top of water rather than sunk. This reminded me of the time I made salad dressing, the oil floated on top so I had to shake vigorously to incorporate it. I also knew that water formed hydrogen bonds which is why water molecules have strong intermolecular forces. However, I did not know that water was a liquid at room temperature rather than a gas such as methane, ethane, fluorine, and carbon dioxide because of the hydrogen bonding. I thought that water molecules and oil molecules were immiscible because they were not attracted to each other, but I learned that they in fact are attracted to each other. I knew what the term hydrophobic meant, after talking about the lotus leaf in class. I always wondered what caused gas to leave a rainbow effect in puddles, I learned that this effect was caused by the oil spreading into an infinitesimally thin layer. Lastly, I learned that polar substances tend to have the preference. I thought it was a mutual agreement between water and oil, but I guess water is too “cliquish” to allow non-polar oil to join the “polar club”.

Sue, Once again excellent writing! 5 huge stars! MW

I could relate this article to the colligative properties we learned in class, one being freezing point depression. Since colligative properties are dependent only on the amount of dissolved material, the greater the number of ions dissolved, the greater the disorder and lower the freezing point. By adding salt to the ice, not only are we adding molecules, but also entropy, which makes it harder for the water molecules to slow down and form a solid. I think the CaCl2 salt would be better than the NaCl salt, since CaCl2 makes more ions. Also, the water molecules and temperature reminded me of our kinetic energy unit. I knew that when the temperature decreased, the water molecules would slow down and become sluggish. One new thing I learned is the phrase "vibrational motion", which is when molecules are still moving, but in the solid phase that motion involves bonds stretching and compressing or the atom wiggling a little bit. I was shocked with the amount of deicing salt used each year in the United States, 15 million tons, that's 30,000,000,000 pounds! After the road is sprinkled with salt, I noticed that the sides of cars start to turn white and "chalky" looking. I now understand why people wash their cars in the winter, to prevent the salt build up which would speed up corrosion.While driving I have seen "bridge may be icy" sign. I thought it was really neat that some bridges have sensors that detect when conditions are right for ice to form so the deicing sprayers know when to activate. I am excited to see what other advances they make in "icy road safety" in the future.
 * Salting Roads**

Sue, What more can I say? Top drawer once more! 5 enormous stars! MW

I have always thought hand warmers were interesting little packages of warmth, but I never really knew how they worked. However from the previous knowledge I have acquired from chemistry class, I knew that an exothermic reaction took place since heat was released. I also knew that the pouches were sealed tightly, to avoid contact with oxygen. I learned that the pouches typically contain iron powder, salt, water, an absorbent material, and activated carbon. I also learned that the iron oxidizes, rusts, when it comes in contact with oxygen. I knew that oxidation of iron was a slow reaction, but I learned that the water and salt act as catalysts to speed up the reaction. I never knew that reusable hand warmers existed. I learned that these warmers contain a supersaturated solution of sodium acetate rather than iron. After doing some further research, I learned that a metal disc creates a seed crystal that starts a chain reaction, which causes the solution to crystallize. This reminded me of the demo in class, when a seed crystal was used to try to start a crystallization process. Lastly, I knew that increasing the surface area of the iron would allow it to react with oxygen more quickly, since reactions involving solids proceed faster if surface area is increased. This is important because we want the hand warmers to activate quickly. While most others would not take the time to evaluate what is happening when they use hand warmers, the next time I use hand warmers I will know what reaction is taking place in my very hands. Sue, Way to take an active role in your education! Once again a great post! 5 stars! MW
 * Hand Warmers**

The first thing I learned is that maple sap is slightly acidic because of the presence of several organic acids. I would have never guessed that sap was slightly acidic, since maple syrup is sweet. I thought it was interesting that the total quantity of acid increases as the season progresses. I also knew that they boiled the sap to remove the water. Since boiling causes the water to evaporate. I knew the removal of water would cause the sap to become more concentrated because the water diluted the sap. I knew that the sap contained either glucose or sucrose. However, I learned that sucrose contains two saccharides, glucose and fructose, which are joined by an alpha glycosidic bond. I realized that the water in the sap is from the glycosidic bond, since water is formed when a glycosidic bond is formed. I learned that another way to remove the water in the sap is by reverse osmosis. I already knew that osmosis is the movement of water from an area of high concentration across a selective semi-permeable membrane to an area of lower concentration. The reading about the reverse osmosis reminded me of the egg experiment we did with the glucose and water. I also learned that sap becomes syrup when the liquid reaches 66-67 degrees Brix. I knew that the boiling point of syrup would be higher than water because it is more viscous and contains sugars. I learned that maple syrup is much more complex than I thought, I never thought syrup would contain minerals such as potassium, calcium, and magnesium. I'm sure this article will pop in my mind the next time I eat a stack of pancakes!
 * The Chemical Compostion of Maple Syrup**

Sue, Your comments about glycosidic bonds are great! They are very important to the understanding of sugar chemistry. 5 supersaturated stars!!!

After reading just the first couple of paragraphs, I was reminded of the “Salting Roads” article we read earlier in the year. I knew that cars in snowy states rust more than cars in mild southern climate states because the salt used for snow and ice causes corrosion. I knew that rusting was an example of a chemical reaction, however I did not know that it was an electro-chemical reaction as well. I remember doing the “iron nail rusting” experiment, but I never gave much thought to what was actually happening. After starting our electrochemistry unit, I knew that iron does not hold onto its electrons very tightly because its standard reduction potential is 0.77, fairly high on the “Standard Reduction Potentials in Aqueous Solution Table”. I learned that physical strains leave stress points in metal, which create anodic regions where the iron is more easily oxidized. I knew that a bridge was needed to connect the potential anodes and cathodes. I learned that engineers must convert rusty iron ore into a pure metal before they place it in one’s car. After reading the sentence, “so they won’t corrode spontaneously”, the thought of a positive delta G popped into my head. Although it would be very cool to cruise the streets in a gold or silver car, I don’t think it is practical and would be very costly. Lastly, I learned that we have high tech paints that release rust inhibitors. I was shocked that the United States spends $276 billion in lost goods and services. I sure hope my car doesn’t flake away soon!
 * Flaking Away**

Sue, Another superlative post! Your posts are a joy to read. 5 shiny rust-free stars! MW