10 Test Tube Mystery
The students were handed 10 test tubes with no identification. The students were supposed to design a method in determining what chemical was in each test tube. The list of chemicals is CuSO4, NH4Cl, NaOH, AgNO3, KI, H2SO4, NaBr, CaCl2, HCl, and Pb(NO3)2. The students are expected to determine the chemicals using physical properties, litmus paper, solubility, and the process of elimination. Physical properties, such as the color, can be determined by sight. Litmus paper can be determined through the change of color, if red then it is an acid, if blue then it is a base. Solubility can be determined through reacting two chemicals together and see if a precipitate is created. Previous knowledge of the solubility rules will help disclose whether two chemicals will or will not create a precipitate. When two chemicals do create a precipitate, it will be easy to determine which chemicals they are. In the end, one chemical will be left over. Safety:
Safety is always the first concern in a lab. Prior to the lab, students were asked to identify where the eye wash station was, the fire extinguisher and blanket were, and the safety shower was. When working with chemicals it is essential to wear safety glasses. Since the students were informed of which chemicals were going to be used prior to the experiment, the students should look at the Material Safety Data Sheet to see what safety concerns may come with the chemicals being used. In the experiment, the students worked with acids. To avoid spilling acids on their persons, the students used syringes to control where the acids were going to be placed. Also, at the end of the experiment, students properly disposed of the laboratory waste and washed their hands, washing away any chemicals that they may have come in contact with. Method:
CuSO4 is blue.
Use litmus paper to find the two acids, H2SO4 and HCl, and the base, NaOH. The litmus paper turned blue for the base and red for...
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