Thursday, January 5, 2012

Types of reactions

     In this lab, we  had a large variety of chemical reactions that go around us at all times. Classifying these reactions helps to make sense of them and enables us to predict the products. This lab gave us an opportunity to learn and apply one classification scheme. There are other classification schemes which you will learn as you continue your study of chemistry. The purpose of this lab activity is to discover the characteristics of different types of reactions.
    Reaction 1: This first reaction we did taking a test tube, filling it 1/2 full with hydrochloric acid, placing the test tube in a rack, and obtaining a piece of magnesium into a test tube holder. Then we got a 2nd test tube, and placed it i the holder. We had our partner place the magnesium strip into a test tube of acid. Immediately we held the second test tube in an inverted position over the tube containing the acid and magnesium. We next held the test tube on top until the chemical reaction stopped, then we wrote down what happened. We tested the gas that was in the first test tube and our partner lit a match and brought the match to the end of the test tube. Once we put the match in the 2nd test tube, it made a sliding/popping noise. The magnesium and HCL reacted immediately. it was pretty cool that once you put the match in the test tube, the gas made a cool noise. I've never seen anything like that happen before.
     Reaction 2: This reaction we started with a bunsen burner, then we took a small strip of magnesium and held it in the flames using tongs. We then wrote down what happened. The results were that it burned extremely bright for a short period of time. The flame is extremely bright and can leave you blinded for a few minutes if you stare at it, so you should be warned before you do the lab to not stare the flame directly.
     Reaction 3: In this reaction, we took a copper wire and shined it up a little using a little piece of sand paper. Using tongs, we held the wire in the flame of the bunsen burner for several minutes.  The copper got really hot, and if you hold it there long enough, it will eventually start to melt. Copper can melt, but it is a patient process, because if you want it to melt it has to heat a lot and finally get the chance to melt once all of the chemicals start to heat up enough.
     Reaction 4: In this reaction, we added a small amount of ammonium carbonate into a test tube, and using a test tube holder and gently heated the test tube and gently wafted the gas coming from the test tube. The gas actually really stunk like ammonia. The smell actually reminded me of horse pee. This was a really weird smell. It stunk pretty bad, and if you smelt it for too long it would give you a pretty big headace.
      Reaction 5: In this reaction, we filled a test tube 1/2 full of hydrogen peroxide and then another small amount of magnanese dioxide to the test tube. Using a test tube holder, immediately we held an inverted test tube over the first tube. When the reaction was complete, we held the test yube upside down, lit a splint, waved the splint until it stopped burning and immediately put the burning splint into the test tube. In doing this, the bubbles came up out of the test tube, and it made a popping noise. Different gasses can make different noises when reacted with different elements.
       Reaction 6: In this reaction, we poured a small amount of pottasium iodide into a test tube, and then poured a small amount of lead nitrate into a second test tube.Then pour both of them into one test tube. When we mixed them together into one test tube, it turned a yellow color. I had no idea that if you mix two gasses together that it can turn a color whrn you mix them.
     Reaction 7: In this reaction, we placed a small amount of copper carbonate into a test tube. We used a test tube holder to heat the test tube while we put a second inverted test tube and test tube holder to collect any of the gas that was given off out of the test tube. The fire that was in one of the test tubes was put out due to the gas fron the tube. It was odd that that happened, because I have never seen a gas that puts out fire. I've always just saeen a gas that makes the fire worse.
       All of these different reactions that we did in this lab taught me a lot about the different reactions that can happen with different gasses and elements. It was a pretty fun lab to do.

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