Pour the contents of one of the test tubes into the other and a reaction should occur and you should see a white precipitate of barium sulfate form. Then, centrifuge it for 1 minute. On the side, weight a boiling test tube containing 2 boiling chips. When the separation is complete, remove the small test tubes from the centrifuge and decant the supernatant into the boiling test tube. Add 1 mL of deionized water to the small test tube containing the precipitate and mix it and centrifuge it for 60 seconds.
In well A2: Place 10 drops of Magnesium Sulfate, MgSO4 c. In well A3: Place 10 drops of Zinc Nitrate, Zn(NO3)2 d. In well A4: Place 10 drops of Iron (III) Chloride, FeCl3 e. In well A5: Place 10 drops of Copper (II) Sulfate, CuSO4 3. Take the metal solids from your LabPaq; there should be one piece each of magnesium, zinc, and iron plus two pieces of lead. NOTE: Magnesium and lead oxidize very easily and an almost invisible oxidation layer may coat the metal. To insure good reactions you should scrape the surface of those metals with a pocketknife or remove the oxidation layer by rubbing the metal pieces with steel wool or something similar. Evidence that a reaction is taking place is the formation of bubbles or a coating on the metal immersed into the solution.
Add hydrochloric acid to a test tube. Cut a piece of magnesium ribbon (couple of centimeters). Record the physical properties of both substances. 2. Write a hypothesis on what you think will happen when mixed.
As you already know, % Copper = mass of copper X 100% mass of sample This first equation will allow you to determine the percent copper in your sample. Another way of expressing this relationship is: % Copper = n(63.55) X 100% f. w. Where: n = the number of copper atoms in the compound 55. = the atomic weight of copper f. w. = the formula weight of the compound Since all of the unknown compounds used in this experiment contain only one copper atom, the second equation gives an easy way of calculating the formula weight of the compound. Purpose: The purpose of this experiment is to determine the percentage of copper and the formula weight of a copper compound. Equipment/Materials: sample of unknown copper compound distilled water electronic balance 250 mL beaker magnesium metal 6 M HCl filter paper ethanol acetone funnel stirring rod watch glasses Safety: • Always wear an apron and goggles in the laboratory.
10-29-10 Analysis of Alum Purpose: To determine if the sample crystals are really aluminum potassium sulfate or alum. Materials: alum, beaker, hot plate, thermometer, thermometer clamp, mortar, pestle, capillary tubes, small rubber bands, stirring rob, goggles. Procedure: Determine the melting point: 1. Pulverize with pestle about 2.00 grams of alum. 2.
Add the HCl SLOWLY to the magnesium by running it down the side of the beaker. Adding the acid too quickly will result in the spattering of the acid. Write down any observations of the reaction. 6. After all the acid has been completely added and the reaction has stopped, use a pipette to add a few extra drops of acid into the beaker until the reaction stops.
Melting Points Lab Abstract: One of the physical properties most relied upon for compound identification is a compound’s melting point. This experiment gives the student an opportunity to explore how compounds can be identified with this physical indicator. The experiment uses two compounds, tetracosane (C24H50) and 1-tetradecanol (C14H30O). The experiment confirms through melting points that the compound with more carbons and no branches (C24H50) has a higher melting point than 1-tetradecanol. Hypothesis: Using melting points can help determine the difference in total carbon atoms and branches between two or more compounds.
6. Combine the iron and copper (II) sulfate together into the distilled water. Heat to a slow boil for 10 minutes. 7. Remove from the heat and allow to cool until you can hold it.
Method Part 1 1 Clean the surface of the 0.5cm piece of magnesium with a piece of steel wool 2 Place the magnesium into a test tube 3 Add three drops of detergent to the test tube 4 Add 2 cm of hydrochloric acid to the test tube. Set timer for 5 minutes and record your observations, including the height of the foam produced in a results table 5 Repeat the process for the
of moles = 4. no. of moles = Stoichiometry is related to the whole number ratios (i) between atoms in chemical formulas and (ii) between reactants and products in a chemical equation. Example 1 A mixture containing only aluminium oxide, Al2O3, and copper (I) oxide, Cu2O, weighs 2.02 g. When heated under a stream of hydrogen, only Cu2O is reduced to metallic copper