The purpose of this lab is to focus on how to make zinc iodide in a different way using compounds instead of elements, which are barium iodide and zinc sulfate. We will see if the reaction between these two compounds will occur and make a prediction by writing a chemical equation. The procedures for this lab are to place a small test tube inside a 50mL beaker and weigh it. Then, using a spatula, add 0.45±0.03 g of zinc sulfate heptahydrate into the small test tube and record the mass. After that, dissolve the sample in 2 mL of deionized water and shake the test tube for 1 to 1 ½ minutes to dissolve the solid.
First I made a water bath by filling the 100 mL beaker with cool tap water. I then placed crushed ice in the 100 mL beaker so the water level was just below the top of the beaker. I sprinkled a little salt in the ice water and mixed it well. I then filled the test tube half full with distilled water and set the test tube in the 24 well plate. I inserted the digital thermometer into the test tube and took reading every 30 seconds until the readings remained constant.
Procedure Step 1, Obtain acid, in a 100 ml Erlenmeyer flask add 35 ml of .2M HCl solution. Step 2, add an indicator to the acid, select the flask and add 2 drops of phenolphthalein indicator. Step 3, Fill buret with NaOH, obtain a 50 ml buret and fill with .2M NaOH solution.Step 4, Titrate NaOH into HCl until end point, record initial buret volume and add NaOH (quickly at first then slowly) until the HCl solution turns pink and record the final buret volume of NaOH in buret. Step 5, repeat steps 1-4 using pH meters, add a pH meter to the acid solution. Record several points of pH and NaOH added (especially near equivalence point) to be use later to prepare a titration curve.
Based on the information from the gram stain, the unknown bacterium was a gram positive. This meant that the next step was a catalase test. A catalase test is done to identify organisms that produce the enzyme catalase and converts hydrogen peroxide into water and gaseous oxygen (1). A catalase test is used to separate staphs from streps in gram-positive cocci. For a catalase test, the bacterium must be placed onto a blood agar plate.
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.
By using the dialysis tubes, we had 3 tubes, filled with the same amount of solute fluid. 8mL of molasses was our solute, once filled in each tube, we tied both ends and placed each individually into 3 beakers of water; one with ice water, another beaker with warm water and lastly a beaker with a room temperature
“Ice…Ice…Baby” “What is the quickest way to melt ice?” January 22, 2013 Abstract We choose to do this experiment in an attempt to discover what the quickest method for melting ice was. The purpose of this project was to find a way to melt the ice off the glass of a car windshield during the cold winter months. Our hypothesis was; if we added water to the ice it would melt quicker then adding either air or salt. The independent variable of the experiment was the molecular structure of the water found in the form of an ice cube. The dependent variable was the “amount” of time it took for all 3-ice cubes to melt.
P5 First I collected four test tubes; in each test tube I purred the solution that has been labelled A, B, C, and D in the container. Then I added a few drops of Iodine solution to the four test tubes. Container A was starch, because the colour changed to blue black, which is test for starch. Starch iodine blue black I purred the three solutions into the sink. Then I purred the solution from the container B, C, and D in to the three
In this lab we synthesized and analyzed potassium aluminum sulfate (KAl(SO4)12H2O) using a multiple different tests. These test included flame test, melting point, potassium test, sulfate test, and aluminum test. We also determined the number of waters of hydration in Alum. Experimentally and empirically potassium aluminum sulfate is a dodecahydrate (4). The purpose of the laboratory is to determine the number of waters of hydration in aluminum potassium sulfate as well as the purity of the Alum we produce.
With increasing temperatures the solute can be dissolved by a solvent during recrystallization. Experimental section Preparation of Chalcone To prepare chalcone 2.1mL of NaOH in was dissolved in 40mL of water and about 25mL of ethanol was added in a 125mL Erlenmeyer flask as soon as pellets were dissolved. Then 0.080 mole of acetophenone was stirred into the 125 mL flask, then place into an ice bath. At once 0.080 moles of bezaldehyde was added to the mixture and stirred all the while temperature was kept between 20-30°C. A stopper was placed on the flask while the mixture was stirring with stirrer for 11/2 hours.