Sleuth your slurry

Our objective for the Sherlock Holmes Experiment was to illustrate that some chemicals can be identified or differentiated by simple chemical tests, such as solubility, pH, or color tests. In our group we had to test come common powders such as Alka-Seltzer, baking soda, flour, Vitamin C (ascorbic acid), and salt. Other chemicals that were used to do this experiment were vinegar, and Iodine 2 Solution. The equipment used to do this experiment was red litmus paper, and 5 test tubes per group.

to the unknown solution in order to completely precipitate the cations in part A. 2 A compound

In reference to the analysis of anions, Table 1 shows that a precipitate was formed when our unknown was combined with HNO3 and AgNO3, thus indicating the presence of a chloride ion. Because our unknown did not form a precipitate due to HCl and BaCl2, separate, effervesce, or smell, we concluded that neither sulfate, nitrate, carbonate nor

Put approximately 9-10(g) copper ore into beaker. Use spatula to break up any large pieces. Next add 17ml H2SO4 (aq) (hydro sulfuric acid) to the beaker. Began mixing until all or most traces of blue dissipate; or the copper ore will no longer dissolve (should appear as a milky liquid). Next use pipette to and remove solution and divide solution into 2 individual test tubes then Place test tubes into centrifuge and run centrifuge for 1 minute. Remove from centrifuge machine Fill a cuvette with the clear solution from the test tube making sure not to disturb the sediment at the bottom. Note the solution should bluish in tint Final place the cuvette in the colorimeter. Then record data and calculate in results section.

again I am going to assume this is soluble since I have not done it yet RC42 17 0 LC33 21 4 SC13 17 4Total 83 54 8

The compound was tested for the presence of ammonium, carbonate, sulfate, chloride, and nitrate, as seen in Table 2. The nitrate test produced a precipitate, indicating the presence of the nitrate ion in the compound. At this point it was hypothesized that our unknown compound was calcium nitrate.

38. When naming binary ionic compounds, write the name of the positive ion (cation) first,

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

This type reaction is known as a double displacement, where two ionic compounds, in this case lead nitrate, Pb(NO3)2(aq) and sodium iodide, NaI(aq), “change partners”. The cation (positive ion) of one compound combines with the anion ( negative ion) of the other to form two new compounds, one aqueous and one being an insoluble product known as a precipitate. To determine which product will be aqueous or a precipitate, the table of solubilities is used. This table helps predict which anions react with cations to produce either soluble or insoluble

In this experiment, the identity of an unknown organic compound will be determined using these methods. Procedure:

Introduction: Using the analytical methods of Gas Chromatography and Mass Spectrometry, in order to determine the composition of a mixture and its individual pure compounds. This is done by analyzing the mixture of compounds using Gas Chromatography and the individual pure compounds by using Mass Spectrometry. Experimental Procedure: Obtain a screw cap and vial which will be ran in the Gas Chromatograph. Fill vial no more than half full of pre prepared unknown compound which is dissolved in either ethanol or acetone. Place vial in Gas Chromatograph and follow the instruction in order to analyze unknown compound.

Introduction: The purpose of this lab is to find the unknown concentration of Cu+2 by comparing the solution to a set of standard concentrations, different known concentrations, which are prepared by diluting approximately 2.5 grams of copper (II) sulfate pentahydrate. A concentration is the amount of solute relative to the volume of a solution, the more solute the more concentrated the solution will be. Concentrations are reported using molarity (M) which is the moles of the solute by the volume of solution in liters.

When one looks back at the procedure of the experiment, trials 1, 2, 3, 4, 5, and 6 all use 6 M HCl for their reactions, and if this were to be substituted for 6 M HNO3, then these reactions would have still taken place, except in trial 2 because copper is less reactive than hydrogen in all cases, but their final observations may yield different colored solids and solutions (Beran,

The cations in both the known and unknown samples were identified by using qualitative analysis, of which were determined to be acidic, basic, or neutral by using litmus paper. Acid-base reactions, oxidation-reduction reactions, and the formation of complex ions are often used in a systematic way for either separating ions or for determining the presence of specific ions. When white precipitate formed after adding hydroxide, aluminum ion was determined to be present in the solution. However, nickel was determined to test positive when the solution changed to a hot pink color after adding a few drops of dimethylglyoxime reagent and iron was present when the solution was a reddish brown color when sodium hydroxide was added to the mixture at the very beginning of the experiment. Qualitative analysis determines that ions will undergo specific chemical reactions with certain reagents to yield observable products to detect the presence of specific ions in an aqueous solution where precipitation reactions play a major role. The qualitative analysis of ions in a mixture must add reagents that exploit the more general properties of ions to separate major groups of ions, separate major groups into subgroups with reactions that will distinguish less general properties, and add reagents that will specifically confirm the presence of individual

In many cases, scientists don’t often have all the details when performing experiments, and there is almost always some aspect that is unknown. In certain scenarios, a chemist may not know what elements or compounds are present in a specific sample, so they must be able to recognize properties characteristic of certain elements and compounds, to determine their presence in the unknown sample. When working with unknown ions, it is often best to use known solubility rules to manipulate, separate, and identify the unknown ions present in a sample. In practice, this usually involves using specific reagents to cause some of the ions to fall out of solution as a solid precipitate, then separating the ions in the precipitate from the ions remaining in solution that are soluble with the specific reagents used. This process is repeated, causing ions to separate either by dissolving them in solutions that they are soluble in, or causing them to form insoluble compounds and fall out of solution as a solid precipitate until the ions have been isolated from each other. Once isolated, the ions are then treated with compounds which react in a distinct manner with specific ions, allowing their identities to be confirmed. In the first portion of this experiment ions are mixed in spot tests with separate reagents, specifically to observe and record the reaction that occurs. These observations can then be used to help