Freedman,+Stacie

Hydrofluoric acid is an extremely dangerous weak acid. It is weak because it the attraction or bond between the hydrogen and fluoride is so strong it cannot easily be broken. The fluoride wants to be stable and gain an electron so it bonds with the hydrogen. This becomes a problem when HF gets on your skin because it easily passes through the dead skin layers to live cells and bonds with the calcium and magnesium in your body because they contain many electrons. This reaction is slow to take place, but cause extreme pain and possibly death.

I found it very interesting that the language we use in chemistry comes from Greek and Latin origins. Taking Latin, I never really gave it much thought that they are the bases for chemistry vocabulary and elements. The term chromatography means writing in color. The first time chromatography was done the different pigments were observed running down the column and this procedure was called chromatography. I also found it interesting that Hydrogen when broken down means water former and when hydrogen is burned it forms water. Lastly the way the polyatomic ions hypochlorite, chlorite, chlorate, and perchlorate are named makes sense when broken down to either mean one more or one less than the base ion.

Stacie,

Good thoughts. I like the chlorate, etc comment!

I read the article Sunny Outlook: Can Sunshine Provide All U.S. Electricity? It was about how the United States uses solar energy now and how we want to use it in the future. I found it interesting how much energy the sun provides, more than eight kilowatt-hours per square meter. Also, I was amazed at how much work is involved with solar energy. The energy is first absorbed through parabolic mirrors and is then used to heat special oil to 400 degrees Celsius. The hot oil is transferred to water which vaporizes and the resulting steam turns a turbine to produce electricity. I think that this type of energy could be very useful in the future if a way to store it is found.

Good thoughts Stacie. MW

Polymers in the Field I knew that science and sports are closely related and often wondered how turf fields are made and installed. I learned about the vulcanization process and how much of a difference it makes in polymers. Without being vulcanized, a polymer does not contain cross section connections and is easily formed into different shapes. Vulcanized polymers can still be deformed, but they will go back to their original shapes. It is very ingenious that they recycle the tires and use them on the turf fields as a cushion for athletes. I found it interesting that the lanes of the track are pre-made in the factory and then assembled onsite.

Well done Stacie. MW

While reading this article I learned that there are intermolecular forces called dipole-induced dipole. They are stronger than dispersion forces and occur when a polar molecule which has a permanent dipole induces a dipole on another non polar molecule. I also learned that when oil and water mix, the oil molecules are more attracted to the water molecules than other oil molecules. This is because of the above described intermolecular force. Lastly I learned that the hydrogen bonding in water is what makes it a liquid at room temperature. Other molecules like water that do not have hydrogen bonding are gases at room temp. This is because hydrogen bonds are stronger than dispersion forces. I already knew that the term hydrophobic means water fearing and is the reason water beads up on wax paper or other non-polar substances. Also, I already knew that dispersion forces create partial charges within a molecule. Lastly I already knew that hydrogen bonds tend to bond with fluorine, oxygen, and nitrogen because they are extremely electronegative. I thought the last paragraph was interesting explaining how when polar and non-polar molecules mix the polar ones call the shots and the non-polar molecules settle for what they can get. Stacie, Well done! I liked that last paragraph explanation also. 5 stars! MW

From reading the article about salting the road, I was able to understand the concepts behind why the roads are salted in the winter. I knew that it was done to prevent cars from slipping on ice and to prevent ice, but know I know the science behind it. Salt is put on roads because it gets in the way of the pure water molecules when they try to form a crystalline solid therefore it lowers the freezing point. If ice is already on the roads adding the salt and with the addition of friction from cars melts the ice and prevents it from crystallizing again. More recently, other salts such as magnesium chloride and calcium chloride have been tested and work better because in solution they dissociate into 3 ions. Also they are easier on cars and the environment.

Good stuff Stacie! 5 stars! MW

I found this article very interesting coming from the standpoint of using hand warmers fairly often. I knew that to make them warmer you have to take them out of your gloves to get them into the air, but I never really put two and two together that the oxygen was needed to fuel the reaction. I also, already knew that iron was the main reactant in the hand warmer packet. I learned though that the exothermic reaction is actually just the iron powder rusting or oxidizing. Lastly, I knew that if the amount of reactants in the packet were increased the reaction would last longer and possibly go faster because of a higher concentration. And lastly I learned through class and this article why the package says do not open hand warmer. I always thought the stuff inside was either poisonous or would just make a mess. It probably would make a mess but the increase in oxygen causes the reaction to take off and it can start smoking because of the intense heat being created.

Stacie, Looks good. Lots of chemistry there! MW

Before reading this article, I already knew that the sap from the maple trees is boiled down using evaporation or reverse osmosis to lower the water content. I also already knew that it took a lot of sap, 40-50 gallons, to make one gallon of syrup. Another thing I already knew was that the sap boils at a higher temp because of the sugar content. The sugar elevates the boiling point 3-4 degrees.. The last thing I already knew was that the crystals form when the syrup cools because the temp drops below the saturation point. Something that I learned was that maple sap contains many different types of acids such as: oxalic, succinic, fumaric, malic, tartaric, citric, and acontic acid. In the early part of the sap season the acid level is low but increases to five times that amount by the end of the season. Another ting I learned was that there are several components that make up maple sap: Sucrose, glucose, primary amines, peptides, amino acids, and other organic compounds. The last thing I learned was that birch sap is half as concentrated as maple sap and more is needed to meet the concentrations of pure maple syrup.

Stacie, Yes I liked that reference to birch syrup. I'd like to try that. :) 5 stars. MW

From this article about rusting I learned that science behind how iron rusts. First the iron is oxidized and the electrons react with the water and oxygen to form the hydroxide ion. The hydroxides then mix with the water and form the ferrous ion. The chemical name for rust is insoluble ferric oxide. Another thing I didn’t know before was rusting is a redox reaction, not just a simple reaction. I already knew that salt speeded up the reaction of rusting forming, but I learned that it accelerates it by making water a better conductor. Also, the chlorine ions form stable complexes with the iron, which makes the corrosion happen quicker. I already knew that paint protected the iron from rusting by covering up and acting as a protective shield. The last thing I already knew is that gold and silver medals don’t rust but they would not be suitable for cars because they are soft and would be extremely expensive.

Stacie, Maybe a gold plated car? Good post. 5 stars. MW