For every 20 drops of solution you will add 0.1g of zinc to the new test tube. Repeat steps 3 and four until the solution is clear. If there ever exists too little of the solution to get enough drops, add up to 1mL of distilled water to the solution. 4. Once the solution is clear, retrieve at least ten drops of the solution and place them in a new test tube.
Objective The purpose of this experiment was to become familiar with the ability to reproduce an experiment several times. Experimental Materials 1 x Magnetic Stirring Bar (yellow) 2 x 100 mL Flask 8 x 50 mL Erlenmeyer flask Magnetic Hotplate Glass Stirring rod Distilled water Pipet (with Pump handle) Starch 0.20M Ammonium Persulfate (NH4)2S2O8 0.20M Ammonium Sulfate (NH4)2S2O4 0.20M Potassium Nitrate (KNO3) 0.20M Potassium Iodide (KI) 1.2 x 10-2M Sodium Thiosulfate (Na2S2O3) Experimental Method 1. All materials were obtained from the classroom. 2. The flasks were thoroughly cleaned with distilled water.
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.
5mL of acidified water will be measured, using a graduated cylinder, and will be transferred to the R tube, and will be immediately vigrously mixed with the reactants. Once the solution turns to an orange or red-brown color, a pipet will be used to quickly remove 30 drops of the solution, then transferred to the C tube, and the mixing will resume until the solution is close to room temperature. The solution will be filtered into the P tube, and the solution that is left in the R tube should be washed three times with 1mL of acidified water each time. The water should then be poured into the P tube, leaving the solid in the R tube. Using a test tube holder, heat the R tube over the Bunsen burner, moving the tube in a circular motion until all the water has evaporated.
Cylinder was rinsed with distilled water. * * 2. 2.0 ppm standard: 2.00 mL of 10.0 ppm phosphate solution was placed in a 25 mL graduated cylinder and diluted to exactly the 10 mL mark with distilled water then poured into a plastic cup labeled 2. Cylinder was rinsed with distilled water. * 3.
Use 10 mL of the stock and dilute to 1 L with distilled water. This gives a 0.01 M solution. 7. Yeast suspension: Add 1 package of dry yeast to 250 mL of 1% sodium bicarbonate solution. Mix thoroughly and swirl when dispensing.
Make sure to keep time, read the spectrometer, and record the data. Note time to the nearest second and mix the contents of tubes 2 and 3 by pouring them back and forth twice. Mixing should be completed within ten seconds. 5) Add the reaction mixture to a cuvette by pouring or using eye dropper, wipe the outside, and place the cuvette in the spectrometer. Read the absorbance at 20 second intervals from the start of the mixing.
Repeat steps 1-5 for trial 2. Variables and Control test: Independent Variable: Amount of each reactant poured into the test tubes Dependent Variable: Height of each solution Constant variables: Amount of time waiting for solution Data Table: Test tube # | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | Trial 1 | 0.5 cm | 1.0 cm | 1.1 cm | 1.5 cm | 1.5 cm | 1.5 cm | 1.3 cm | 1.5 cm | Trial 2 | 0.5 cm | 0.7 cm | 1.0 cm | 1.0 cm | 1.3 cm | 1.7 cm | 1.9 cm | 1.5 cm | Observation/Analysis: Solution turns yellow when a separate product is added, solid of the solution leaks down to the bottom after 20 minutes. Conclusion: The group tried to find the excess or limiting for the reaction between KI and Pb. In the end the hypothesis was supported by the data. We found that little amounts of each product led to a greater height of solids.
Put exactly 5.0 mL of water in the 10.0 mL graduated cylinder. Record this volume in your data table (10.0 mL). Label the first pipet "Acid." To calibrate the pipet, fill it with LIU-2 water. Holding the pipet vertically, add 20 drops of water to the cylinder.
In this experiment, a chromatography column was pre-created in a plastic tube containing glass beads with microscopic holes and an excess of buffer solution. After draining the initial buffer solution to the top of the column bed, 25 microliters of a hemoglobin (Hb)/vitamin B12 mixture sample were pipetted into the top opening of the column using a P200 pipette instrument. After a few minutes, the mixture began to separate within the column tube. 25 microliters of the buffer solution were then added to the column, using the P200 pipette instrument, to continue the chromatography process and prevent the column from drying. Drops from the column were collected from this point on, using 10 collection tubes labeled 1-10.