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.
Do an initial Benedict's test on the 15% glucose/1% starch and the beaker solutions for glucose by putting some of the solution and a roughly equal amount of blue Benedict's solution in a test tube, placing the test tube in boiling water for 90 seconds, and observing whether or not the solution changes color from blue. 3. Form a bag out of dialysis tubing by tying off one end, putting in enough 15% glucose/1% starch solution to fill it halfway, and tying off the other end leaving the other half of the bag void of anything (even air). Write down the solution's color. 4.
The fact that the energy needed to break the necessary bonds falls within the visible light spectrum is the basis on which the experiment is based. This brings up the issue of selectivity. For example, the bromine radical is more selective than the chlorine radical. This has to do with electronegativity. It is known that chlorine is more electronegative than bromine, and thus chlorine is more reactive, and less discriminatory as to what it will react with, thus making bromine more “selective”.
Experiment Colligative Properties & Osmotic Pressure Karen Curry 1/19/2014 1:00pm Abstract The purpose of this experiment is to understand and compare the difference of the freezing points between pure solvents in a solution and a non-volatile solute. Secondly, osmosis is demonstrated in a permeable membrane in this case a dialysis tubing and a less permeable membrane with a much harder shell like the egg. Experiment and Observation Starting with Part I of this experiment I gathered together all my items I needed. Small rubber band, salt, tap water, distilled water, 1/8 teaspoon measuring spoon, crushed ice, beaker 100 mL plastic, stopwatch-digital, test tube 13 x 100 mm, digital thermometer, well plate-24. First I made a water bath by filling the 100 mL beaker with cool tap water.
Viscosity can be affected by three main factors, Firstly, the higher the temperature, the lower the density of the magma, causing it to flow more easily. Secondly, the greater the amount of dissolved gases in the magma, the less viscous it will be, and lastly the higher the silica content, the more viscous it will be. Thicker, more viscous magma has a greater potential for explosive eruptions and therefore represent the greatest potential hazards. The thickest type of magma is known as Acidic Magma. Its relatively low temperature, high silica content and leads to blockages and powerful eruptions.
Osmosis and Diffusion Across a Semi-permeable Membrane Description of the Content of the beakers at initial set up: Beaker 1 had 4 pipettes of starch and 4 pipettes of amylase in a dialysis bag, which was placed into a surrounding liquid containing 2/3 water and 4 full droppers of Lugol’s solution. The color of the dialysis bag was clear and the surrounding liquid was amber in color. Beaker 2 had 8 pipettes of starch in a dialysis bag, which was placed into a surrounding liquid containing 2/3 water and 4 full droppers of Lugol’s solution. The color of the dialysis bag was clear and the surrounding liquid was amber in color. Description of the Content of the beakers after 1 hour The dialysis bag in beaker 1 had an amber color to it and the surrounding liquid was still amber.
9/17/2011 Experiment 1: The Mole Concept and the Chemical Formula of a Hydrate Purpose: The purpose of this lab is to learn about the concept of the mole by converting mass measurements, calculating the number of moles in a substance, and calculating the number of moles of water released by a hydrate. With these calculations, one is able to determine the empirical formula of a hydrate from the formula of an anhydrous compound. Procedure: After reading the lab, I went to the store and gathered the materials that were required but not supplied by the lab pack. After I returned, I put on my safety glasses and laid out all the materials that were going to be used in the lab. I realized that the lab did not include 2 aluminum cups used for the experiments so I decided to make them out of aluminum foil.
While stirring, 6 M NaOH was added drop-wise until the solution became basic, turning red litmus paper blue. A total of 3.84 mL NaOH was required to achieve this; the resulting solution appearing dark blue with cloudy precipitates. The solution was then heated gently atop a hot plate to catalyze the next reaction, with care taken to assure all residue was kept off the walls of the beaker. Heating continued until the reaction reached completion and the solution slowly changed from blue to a dark green and finally black. At this point the heat was turned off to allow the black solid in the beaker, CuO, to settle to the bottom.
At the bottom of the petri dishes we level it with four quadrants to make sure that each of the antibiotics were placed in the right quadrant and be able to see how the bacteria acted in respect to the placement of the antibiotic. One of the quadrants was kept as the control of the experiment. There were six antibiotic but each group obtain only three of the antibiotic for each bacteria. When placing the bacteria on the petri dish we used a pipette to obtain 100uL of the bacteria onto the petri dish. With a rod (spreader) that was dip in ethanol and then place under the busen burner in order to neutralize it; we spread the bacteria on every surface area of the petri dish.
Once the copper had reacted completely, the fume hood was removed and 10 mL of distilled water was added to the beaker. 6 M NaOH was then added drop wise until the solution turned red litmus paper blue. Once this happened, the solution was heated on medium level and constantly stirred with a stir bar until the solution turned black and then sat to cool for about two minutes. Distilled water was added periodically throughout heating to ensure the solution didn’t dry out. After the solution had cooled, the excess liquid was decanted out by slowly pouring it out