Drescher,+Nicolette

**Ariticle #1**
I didn’t know that when we burn ourselves on something hot, it is the high temperature that kills our cells. Yet with chemical burns, our cells are killed by a chemical reaction on the surface of our skin. I found it interesting how chemical burns relate to the reactions we are studying in class. In this particular case the man obtained HF on his hand, which is a weak acid. The bond is relatively stable but under the right conditions, the bond can be broken. In the story it explains how fluoride is electron-hungry and will latch onto chemicals that can provide electrons, and in this case it attached with calcium and magnesium. I also found it interesting that because the doctor knew this chemical reaction, he knew that in order to help save the man’s hand, he needed to inject calcium because the fluoride in the HF attached with the calcium in his skin tissues causing low levels of calcium.

====**Article #2** I found it interesting how the names of the chemical elements were all derived from Greek prefixes and suffixes. I did not know that the names came from the Greek nor did I know that they all had specific meanings to them. The chemical elements that I found the meaning of their name to be the most interesting were Hydrogen, Phosphorus, and Chlorine. Hydrogen was derived from the Greek roots Hydro+gen meaning "water former". I found this interesting because when hydrogen burns, water is formed. Phosporus comes from the Greek roots Phos+Phero meaning "light bearer". This was interesting to me because it states that Phosphorus emits light in the dark which the name fits perfectly. Lastly Chlorine comes from the Greek root Khloros which means "greenish yellow". When I read this I thought of the word Chlorophyl, which is what gives leaves their greenish yellow color and wondered if the word aslo came from the Greek root "Khloros." Not only are chemical elements' names from the Greek, but so are classes of compounds, general words, chemical compounds, and Organic Chemistry terms. Knowing Greek roots can really help you understand the meaning of these Chemistry words.====

Niki,

Great post! You found several interesting things!


 * Article #3 :Alternative Energy Sources**

I read the article called, “ Is the Hydrogen Car of the Future Running on Empty?” I never knew that such things as hydrogen cars existed and I found it very interesting how they work. Hydrogen cars contain hydrogen in their gas tanks, and use the hydrogen to power its fuel cell. Hydrogen cars are said to be beneficial because they are a lot cleaner than standard cars– with water vapor being given off rather than harmful pollutants. The Hydrogen is oxidized and produces electricity, making the car run. One of the car’s greatest aspects is its easy-to-read gauge, letting the driver know what the car is doing. Although the hydrogen car is said to be beneficial, there are many downfalls. The major drawback to the hydrogen car is the lack of nationwide hydrogen distribution and refueling stations. Hydrogen is not as easy to obtain as gasoline is, leaving people questioning how we are going to get more hydrogen service stations, when there is not a high demand for hydrogen cars. I think that the production of hydrogen cars with stand at a halt for a while, until we are desperately in need of an alternative energy source to incorporate with gasoline. Niki, If hydrogen cars catch on they will probably start in urban areas most likely in California. MW


 * Polymers in the field **

After I read this article I learned many things about our track and field that I didn’t know before. When I was on our field I never really thought about what it was made out of. Whenever we had gym class though, I noticed the heat the field gave off. We would all complain about how out it was and how much hotter it was on the field. I learned that because the grass blades are dyed green, they strongly absorb solar radiation. I thought the temperature was due to the black granules. I also found it very interesting that you can put water on the Astroturf and when it evaporates the water carries thermal energy away in the same way sweat cools our body. In addition I never knew that the track consisted of a double layer of vulcanized rubber. I also learned what vulcanization was - a process that cross-links long elastomer chains resulting a polymer mass that is a solid rather than a highly viscous liquid. Whenever my dad would talk about work he would use the word polymer and I never knew what he was talking about so it was nice to learn about it. I found it interesting that gum was an elastic polymer in addition to rubber bands.

Great connection to outside world! MW


 * Oil and Water**

Before reading this article I knew that oil and water didn't mix because water was polar and oil was nonpolar, but I never really thought about the reason that oil floats on water is because it is less dense. I also knew that water molecules contained hydrogen bonding and dipole-dipole forces and oil molecules contained London forces. What I didn't know was that the reason water was a liquid at room temperature was because the hydrogen bonding contributes a substantial amount of cohesive energy, over and above the London forces present whereas molecules of the same size are gases at room temperature because they are nonpolar. I knew what the term hydrophobic meant from your demonstration in class and that oil was hdrophobic because it is nonpolar. I found it interesting that oil molecules would rather surround themselves with water molecules than oil molecules and never knew this before. I thought since oil and water didn't mix that they did not have an attraction between eachother when in reality they do.

Niki, Good post. Well-documented! MW 5 stars!


 * Salting Roads**


 * I knew that salt was used to melt the ice on roads but I didn't know that it can cause rust and corrosion on cars, bridges, and other parts of the highway. I also didn't know that highway workers used salt to prevent ice from forming on the road in addition to melting the ice already on the road. I found it interesting how salting the roads before a snowstorm prevents the roads from freezing because i never really knew how it worked. Highway workers spread salt on the roads before a storm and because the road is warmer than the air the snow melts on the roads mixing with the salt to create a solution. Because this solution has salt in it, the freezing point is lower and the solution will not freeze as easily as pure water. I also learned that as the temperature decreases so does the solubility of salt in water. The eutectic temperature is the lowest temperature that a mixture of two or more substances can stay liquified. I didn't know that the greater number of dissolved particles determines the extent of the lowering of the freezing point of a solution, so MgCl2 and CaCl2 are better salts to use than NaCl. I thought it was a smart idea to install sensors that can detect when conditions are right to form ice on bridges and have deicer sprayers that spray liquid on the roads to keep them from freezing.

Niki, Very thorough! 5 stars! MW

Hand warmers**

Reading this article reminded me of that chilling day back in October when I had my golf districts. The night before my match I thought of how I was going to stay warm and decided to try hand warmers. The day of the match hand warmers seemed like the greatest invention ever to all of us golfers and even to the spectators. I knew that hand warmers were exothermic reactions, giving off heat as they were exposed to air. I remember wondering what was inside of the pouches while I was playing and now know that they typically contain iron powder, salt, water, an absorbent material, and activated carbon. I knew that specific packaging was used for the pouches to help prevent air from entering and causing the reaction to start, and was reminded by my dad not to open them until I started playing and needed them. As you take out the hand warmers from their packaging, oxygen drifts across the pouch's permeable covering and reacts with the iron powder forming iron oxide while releasing heat. I didn't know that increasing the amount of iron powder increased the length of the hand warmer's life. I was outside for eight hours that day and was glad to have my hand warmers last all day. After learning a little about reactions, I knew that increasing the surface area of the iron powder in the pouches, the faster the pouch would heat up. This article was very interesting because I didn't know exactly how the handwarmers worked, I only knew that they were amazing and the best purchase that day.

Niki, Good story! I hope you can appreciate the chemistry behind these devices as you learn more about thermodynamics and reaction rates. :) MW

I didn't know that sap starts the season with a low quantity of acid and and progressively increases as the season goes on. Is it a good thing or a bad thing for the sap to be acidic? I found it interesting that i could relate our unit on solubility with maple syrup because since the minerals in sap are nonvolatile, the mineral salts of the organic acids present in sap may not be soluble in finished syrup, causing precipitation. I knew that a lot of water needed to be removed in order to make maple syrup but I was really shocked when i read that it takes 40-50 gallons of sap to make only one gallon of maple syrup. I knew that syrup boils at a higher temperature than pure water because it is more concentrated and by increasing the concentration, the boiling point also increases. I know understand that maple syrup is brown because of the chemical reactions that are occurring in the sap instead of white when sap evaporates and dries. Lastly, I knew that as hot sap evaporated into syrup the solubility of salts remains high but when the finished product is cooled, the solubility of salts drops. This is because things are more soluble when they are warm.
 * The Chemical Composition of Maple Syrup**

Niki, OK. Most salts and sugars particularly in this case are more soluble at higher temps. 5 stars. MW


 * __Flaking Away__**

Not being a car enthusiast, I didn’t know that cars are made mostly of steel, a tough mixture of iron, carbon, and small amounts of other ingredients like manganese, silicon, phosphorus, and sulfur. However, I did know that cars tend to rust more in snowy regions and coastal towns because I remember my dad telling me this. He told me this when I asked him why we didn’t take his car to the beach. From our lesson I also knew that rust is a chemical reaction that involves two reactions; reduction, gain of electrons, and oxidation, loss of electrons. In addition, I knew that the redox reaction needs an anode, cathode, and electrolyte solution to take place. I didn’t know that chloride ions form very stable complex ions with Fe3+, which helps dissolve iron and accelerate corrosion and this is why having a car in a snowy region or coastal town causing the car to rust quicker. Another thing that I didn’t know and found interesting was, that because iron rarely exists in a pure state in nature, engineers must convert rusty iron ore into a pure metal for it to be used in your car. Everyone usually thinks that things start out pure and end worse then they started.

Niki, Good post! 5 shiny stars. MW