Abstract The purpose of the experiment was to identify unknown ionic compound #. After many tests, the unknown was identified as sodium chloride. The cation (Na+) was determined by having a yellow/orange color flame test. The anion (Cl-) was determined by the chloride anion test when the unknown test solution showed a positive test for chloride. The synthesis of NaCl further identified the ionic compound by reacting sodium hydroxide and hydrochloric acid and obtaining solid sodium chloride.
Theoretically speaking, if we use one granule of zinc and one granule of iodine opposed to one granule of Barium Iodide and one granule of Zinc Sulfate, the cost would be $.2123 in total for the elemental reaction and $.9265 for the double replacement reaction. In terms of safety, it is safe to say that the safer thing would be centrifuging since we are
Ethan D. Wilhelm September 10, 2012 Chemistry 121 section 8 Friday 9-12 Sarah Gains Unknown Substance Lab Purpose: The purpose of this lab was to identify an unknown substance B by finding enough of its physical properties that we could eliminate all substances it can’t be. We use micro lab to help us find the boiling point, freezing point and mass. Then we tested the solubility of the unknown substance in water, hexane, and Alcohol. With this information we were able to find the identity of the unknown substance B. Procedure: Throughout this lab we were finding the physical properties of substance B.
For example, if you mix aqueous solutions of AgNO3 and NaCl, there are two new combinations of ions possible. The silver nitrate solution contains Ag+(aq) and NO3-(aq). The sodium chloride contains Na+(aq) and Cl-(aq). Possible new combinations of these ions are AgCl and NaNO3. Note: these formulas would have been written in the upper right hand corner of each box before beginning the lab.
What is the theoretical percent zinc in a sample of zinc iodide? 65.39 g Zn/(253.8 g I2+65.39g Zn) *10020.49 % zinc 2. How does your percent zinc in a sample of zinc iodide you analyzed in lab compare with theoretical
For the identification test for the gray solid, we all concluded that this substance showed negative results for every chemical tested except for the zinc metal. In other words, this gray solid only significantly reacted with HCl, indicating the presence of zinc metal. However, our test for the iodide ion with the gray solid, where we added AgNO3 to the gray solid, was very unclear as we did see a yellow liquid, which we could not decide whether it was a precipitate of AgI. Other substances produced a clear precipitate but this one did not. So we concluded that this Zinc did not contain significant amounts of iodide ion.
However, in ordinary conductors such as copper and silver, impurities and other defects impose a lower limit. Even near absolute zero a real sample of copper shows a non-zero resistance. The resistance of a superconductor, on the other hand, drops abruptly to zero when the material is cooled below its "critical temperature". An electric current flowing in a loop of superconducting wire can persist indefinitely with no power source. The matter of thermodynamics underlines the book with the key ingredient to the subject of absolute zero.
This was done by taking small amounts of the unknown acid. It was then placed into capillary tubes and inserted into the Bibby Sterilin Device. Starting with a high plateau to find a quick melting point and then proceeding to find an actual melting point. The next experiment that aided in finding more characterizations of unknown #2651145-PLF13 was equivalent weight. In order to find the equivalent weight a titration of the unknown acid had to be conducted.
The purpose of this lab was to find the molecular weight of two unknown substances by analyzing the freezing points in cyclohexane and to provide a visual representation of the freezing point depression effect. The theory of this lab is; by using measurements of mass of the unknown substances (solute) in correlation with the mass of the cyclohexane (solvent) and the freezing point constant of the solvent, you could determine the molecular weight of the solute by using the same math involved in deciding the freezing point of the solution/ The theory behind the visual of the FPD effect is that if one was to record the freezing point of a solution and two solutions of the same substances with more solute, one would see a visible drop in freezing point. The equations you needed for this lab were the freezing point formula for organic substances (ΔFp=(m)Kf) and the
Only certain type of numbers showed the error, while most users would never encounter the flaw. On June 13, 1994, Dr. Thomas Nicely discovered that some of his calculations done on a computer with the new Pentium chip came back incorrect. He only discovered this because of earlier calculations done on other computers resulted in different amounts. He was only able to deduce that it was something wrong with the new Pentium chip by eliminating all other factors, such as the motherboard chipset or programming errors. On October 24,1994, Dr. Nicely notified Intel about his findings.