Identify And Distinguish Between Ions In The Halide Family Analysis

2. Write a statement to explain the molecular composition of the unknown solution based on the results obtained during testing with the Biuret solution and each sample solution.

To determine which ions are present in the two unknown solutions. This will be accomplished by mixing three known solutions with three testing solutions. You will use this information to determine which ions are present in the unknown solutions.

For example, silver nitrate formed a white precipitate when it was tested with ammonium chloride. In contrast, unknown 3 did not formed any precipitate with ammonium chloride. Ammonium chloride change the color of unknown 3 to a light green while the solution of silver nitrate and ammonium chloride was cloudy white solution. Likewise, the metal in unknown 3 could have been Calcium neither. Data and observation shows that calcium nitrate whether formed a white precipitate or did not react at all while unknown 3 formed an orange precipitate. Therefore, silver and calcium are not the two metal present in unknown

They ruled this combination out by comparing its physical and chemical properties to those of the mystery mixture. One of the differences between the mystery mixture and the mixture of MgSO4, C6H8O7, and NaHCO3 is during the chemical reaction. During the reaction of the mystery mixture the bubbles and only about one centimeter high. During the reaction of MgSO4, C6H8O7, and NaHCO3, the bubbles were approximately one inch tall. Another difference during the chemical reaction was the time that the two mixtures fizzed. The mystery mixture fizzed for about 3 minutes and 14 seconds. The combination of MgSO4, C6H8O7, and NaHCO3 fizzed for approximately 5 minutes and 47 seconds. Thirdly, the eighth-grade scientists decided to eliminate MgSO4, C6H8O7, and NaHCO3 as a possibility to be the mystery mixture because during the reaction the mystery mixture's temperature was 16.5oC at the end of the reaction. While the combination of MgSO4, C6H8O7, and NaHCO3 ended up at 17.6oC. Finally, the scientist knew that they could rule out the mixture of MgSO4, C6H8O7, and NaHCO3 is because they noticed that the chunks in the mystery mixture were not shiny, but very dull, and the lumps in the mix of MgSO4, C6H8O7, and NaHCO3

Many signs show that a chemical reaction has occurred. Some ways we know there is a chemical reaction are the formation of gas, formation of precipitate, change in temperature, and,or change in color. In part one of the experiment, we know there was a chemical change because of the formation of the white precipitate. We poured the ammonia and water in the flask with alum and water, forming a white, cloudy substance in between the two liquids. The white, cloudy substance between the two is liquids is also known as aluminum hydroxide. The second part of the experiment was very similar to the first, but in the second part we mixed epon salt, water, and ammonia. The precipitate formed from mixing the epson salt, water, and ammonia was called magnesium hydroxide.

For the cation analysis, 0.566 g of an unknown compound was dissolved completely in 5mL of distilled water in a centrifuge tube, thus confirming this solution as a stock solution. A flame test was performed on the stock solution to give a general idea of what test was to e preformed on the stock solution deriving the information from our logic trees in part 1. The logic tree from part 1 and the flame test confirmed that we needed to conduct an ammonia test on the stock solution. To being the ammonia test, 15 M NH4OH was added drop wise (about 20 drops) to the stock and the color of the solution and the color of the solution was recorded. 10 more drops of 15 M NH4OH

With the addition of Dithizone, both the unknown and silver formed colloidal solutions with gray particles, so the unknown was likely silver.

Identifying an unknown substance can be accomplished with the use of multiple scientific tests, which help narrow down the possibilities of the unknown compound. The unknown substance that I was given was unknown number A84841BIR, and posed to be a real challenge since I needed to test two different molecular combinations for this specific substance. Once the number of moles in substance was calculated using the ideal gas law, I divided it from the sample mass number after heating and obtained that the molarity of my unknown chemical was 58.93 g/mol. To find my molecular formula I calculated the mass of each element, then the moles, lastly I took the smallest whole-number ratio. Using the molarity calculated I was able to do some research to get a better understanding about what my unknown chemical could possibly be. Once I’ve collected all my data together and strenuously researched the web for articles relating to understanding Infa-Red spectroscopy, I should be able to make an educated guess upon what my unknown solution could be.

Unknown 2: Silver ; Unknown 2 Forms precipitate with HCl, then confirms by turning black with NaOH. It remains clear when tested with NaOH after silver removal indicating that iron is not present. No reaction takes place during the reaction with SCN and HCl further indicating that iron is not present. Potassium ferrocyanide does not form a blue precipitate indicating that zinc is not present. Therefore unknown two only contains silver.

The previous steps were repeated for the remaining known salts and also the two unknown salts. 9. All flame colours were observed and recorded. 10.

In this lab students tested the given contaminated (hard water) for the ions present in the water prior to the distillation, and then after the distillate (pure water) was collected, the same procedures were followed to prove the absence of the hard water contaminates. SPAN Chemistry is so called because this dual-credit class spans the gap between high school and the extremely rigorous college chemistry expectations.

To find the unknown #8 Alkaline I realized that the only anion that had 4 distinct precipitate reactions for each alkaline was H2SO4, so all I had to do was react Unknown #8 with H2SO4. I did this experiment and the reactant was milky white. Based on this reaction in comparison to my previous reactions I concluded that unknown #8 alkaline was the alkaline earth Ba. This experiment was most efficient because it only took one step to figure out what my unknown was, since their was four different reaction outcomes and four different earth metal each matching to one out come this was clearly the most efficient way.

Background A chemical equation that is in equilibrium will naturally balance itself out should either the products are the reactants be increased, or other stresses such as temperature and pressure are placed on it. However, as with a lever in physics, the fulcrum or balancing point is not always in the middle. In most cases, one side of the equation will be favored more. Ergo, the equation will try to balance to this point of equilibrium.

In this lab, a lab group will do multiple tests on water for contrasting ions. Tests confirming the absence or presence of the ion. The lab group will be dealing with five distinct solutions. A control sample, tap water sample, ocean water sample, and a distilled water sample. The group will also use a reference solution. A reference solution is a solution with a firm vigorous existence of the ion being tested. So, It is like an example of what the precipitate should look like when the ion is existent and visible in the water sample. The solution may or may not contain an ion. Compare the results with the performance of the reference sample. Finally, if an ion is present, a chemical reaction will happen, making either a precipitate or a solution

In Part III, in reaction to Ca(NO3)2, the unknown halogen's solution turned cloudy and formed a precipitate. This reaction means that the unknown halogen could either be NaF or NaBr. In reaction to AgNO3 and NH4OH, the unknown halogen has no reaction. These non-reactions eliminate NaBr as an option, so the unknown halogen must be NaF, which was later confirmed true by the teacher.