Classes of Chemical Reactions

Classes of Chemical Reactions

Whenever a reaction takes place, energy is changed as well when the substances react chemically. Scientists have taken these changes in energy and generalized them. Scientists can take these generalizations and discover more about the nature and tendencies of matter. In this lab, the purpose was to perform seven reactions, write down their equations, and identify the type of reaction. In this lab report, several methods of displaying this information will be applied.

Synthesis

1. A piece of Magnesium was obtained at about two centimeters in length. The strip was thin and easily bent or twisted. It had a metallic surface and was brittle. It was silver in color. A flame from a Bunsen burner was held to the Mg, and it ignited, giving off a brilliant white light. Looking directly into the light resulted in temporary blindness, which would explain the warning on the procedures that strongly suggested not looking directly into the light. After the flame had extinguished itself due to lack of fuel, the Mg had turned from a metallic strip to an off-white powder, which crumbled at the slightest irritation. The magnesium had bonded with the oxygen gas in the air from the energy that was applied to it and formed magnesium oxide. The type of reaction was a synthesis reaction, as is shown by this equation.

2Mg(s) + O2(g) = 2MgO(s)

2. A piece of copper was obtained. It was a small, rounded wire that could be bent, although with a greater difficulty than the Mg strip from the previous account. It was copper in color (never saw that one coming, didja) and had a metallic luster. The copper was put in the flame of a Bunsen burner and after several seconds, it began to blacken. The flame was applied to it for about a minute and a half, and the copper appeared silvery under intense heat, but when it was removed from the flame, the silver color quickly faded. The copper strip was now black all over, and the change in color suggested that a chemical change had occurred. The Cu had reacted with the oxygen in the air and formed copper oxide. The black color could be scraped off, but only in small slivers. It would crumble when it was irritated with a great deal of pressure, respectively. It was a synthesis reaction as displayed by the equation here.

Cu(s) + O2(o) = CuO2

Decomposition

3. Being a splint is not easy. We come out of production and are shipped to laboratories across the country. Luckily for us, we are made from wood that possesses the very "useful" quality of maintaining a flame. Once we make it to the lab, someone decides they need to light some infernal gas on fire, and that's the end of us. It really isn't as bad as it sounds, because burning is one thing we are quite good at. To put a silver lining on it, we haven't got it nearly as bad as those wretched toothpicks. Anyway, here I am, the splint selected to test some awful gas that was produced after a green, clumpy powder was dropped into a test tube. I overheard the name copper (II) carbonate, and some one talking about keeping it off their skin because it is poisonous. Anyways, it looks like the copper carbonate is about as well off as I am, because it looks like the "scientists" are holding a burning pillar of death they refer to as