10 drops of each cation that are left are added to clean centrifuge tubes. 15M NH4OH was added dropwise until a color change or a precipitate was formed with no more than 20 drops added. A cation should be eliminated. If the solution formed a precipitate before, then 10 more drops of the 15M NH4OH was added to the solution. The last two cations should be separated with the observations of the additional NH4OH added.
Mount the buret on the ringstand and fill it above the zero mark with the prepared sodium hydroxide solution. Open the stopcock and allow the buret to drain until the liquid level is at zero. Make sure all the air bubbles are out of the tip of the buret. Read and record the intial buret reading to the 0.01mL. Place the 125mL flask containing the first KHP
10 drops of NaOH were added to each precipitate to test for amphoteric species. The contents were rinsed with distilled water and the tubes were cleaned with 6 M HCl. For the ammonia elimination test, 10 drops of each cation solution were placed in their tubes and 15 M NH4OH were added dropwise till a precipitate or color complex was observed or till 20 drops were reached. 10 drops of 15 M NH4OH were added and additional changes were recorded. The contents were disposed of and rinsed with distilled water.
By ways of decanting (using a class stirring rod to guide solution), pour the solution into the funnel until it is about half an inch from the top. The solution should be clear and colorless 8) Allow the flask to cool. While the flask and solution are cooling, wash the funnel and beaker with LOTS of tap water to remove all traces of KOH. Also throw away any carbon on the filter paper. 9) Once the solution is cool enough to touch, add 35mL of 3M H2SO4 (measured out in 50mL graduated cylinder) SLOWLY AND STIR CONSTANLY.
Write down everything you notice. Remove test tube from water and allow it to cool for 2 minutes in a small beaker of tap water. Add about 7.0 mL of 1M hydrochloric acid to the tube. Mix chemicals very thoroughly with a stirring rod. Record how long it takes for change to happen.
Next, obtain a 5 mL serological pipet and thoroughly rinse it with the buffer solution, then discard the buffer solution into the 250 mL beaker. Now, use the pipet to distribute 5 mL of the buffer solution into three 50 mL beakers. Be sure that the 50 mL beakers have been cleaned are dried prior to this. Next, locate the three pre filled burets in the lab room. Find the buret labeled 1.0M HCl and add exactly 1.00 mL of HCl to just one of the three 50 mL beakers with buffer solution already in them.
Next, take out the filter paper and add 50 mL of water. Pour the solution into the vacuum flask and decant evenly into two beakers. Add 1 mL of 0.1 M potassium phosphate into the first beaker. It is negative and indicated no excess lead ion in the solution. Add 1 mL of 0.1 M silver nitrate into the second beaker.
In this experiment, the salicylic acid is insoluble in cold water and can be collected by vacuum filtration. Procedure As the lab, synthesis of salicylic acid, had done, micro-scale was used. To begin, 3.5mL of water was poured into a 10 mL round-bottomed flask. And 0.48 g of sodium hydroxide was added to the flask. After the solid was dissolved, 230mg of methyl salicylate was added using a graduated pipet to the NaOH solution.
The Effect of Salt on the Boiling Point of Water Purpose: The purpose of this experiment was to test the effect of salt on the boiling point of water. Materials: Three 500 ML beakers Hot Plate Weighing cup Scale Salt Distilled water Thermometer Stirrer Hypothesis: If more salt is added to water then, the boiling point will increase. Independent variable: The dependent variable is the amount of salt put into each beaker filled with 200 ML of water. Dependent Variable: The dependent variable of this experiment is the boiling point of all the different beakers. Control: The control of this experiment is the one beaker filled with 200 ML of water and no salt.
Materials and Methods Part 1 For the cation elimination test first 10 drops of potassium, iron (III), zinc (II), copper (II), and cobalt (II) were added to 5 centrifuge tubes and the color was recorded. Then for the metal hydroxide test, 6 M NaOH was added drop wise till a precipitate was formed. Each solution except potassium formed a precipitate, so then 10 additional drops of NaOH were added to the remaining solutions. Tubes were cleaned with distilled water and 6 M HCL. Next was the ammonia test 10 drops of each metal solution were added to new centrifuge tubes and 15 M NH4OH was added until the solution changed color or a precipitate was formed.