(追加200分)帮忙修改语法问题
The concept of this lab was to validate the law of conservation of mass by using copper and sulfur. It was a chemical compound and both of them are synthetic materials that we used to observe the changes between the beginning and the consequences of the end of the experiment. The properties of these two pure elements copper and sulfur were ready to combine and to form a compound of copper sulfide. The major observations of this lab were that we wanted to know the chemical and physical reactions and the states of matter which were the transformation and the changes in appearance of a substance. For example, using the chemical substance, it always happens in a molecule level. Copper and sulfur, we were looking for the changes in mass, smelling differences, color changing, and among others; these are some instances of chemical reactions. I was forced on the physical changes; the shape of the substance and the color appearances had changed into next level which was the consequences. They caused a change in the states of matter which forced on motion, temperature, and pressure.
Throughout this lab, I learned many methods to figure the reactions out.When the Sulfur heated evaporates into yellow vapor or gas because of its phase transition (from solid to liquid), and the copper was burned black and melted a little bit. They mixed together; later, it reacted with copper in a simple reaction: Cu + S = CuS. Before heating the test tube, the mass was greater than after heating it, because the sulfur and copper were dissolved by the hot temperature, then some of the molecules disappeared. Chemical changes often happen on a much smaller scale, while the experiment shows obvious reactions such as color change and changes between molecules.
The data of below show the properties, chemical and physical changes, and the changes in mass. It is important to find out the conservation of laws because the synthesis of a compound of copper and sulfur attracted interest because theirs potentials. My experiment had a good result due to my change was 0.34 and the percentage of source error was 10.9% which are a good conservation. The class change was 0.57 which is not bad and with 1.99% source of error. An effective result of this measurement was the change of mass, a great experiment of this chemical compound can be had a mass that approach to zero gram. Accordingly, my class had a wonderful effect.