Procedure: 1. Fill a beaker two-thirds full of water and add approximately 20 drops of IKI. Write down the solution's color and record the mass of the bag. 2. 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.
Add 1 mL of deionized water to the small test tube containing the precipitate and mix it and centrifuge it for 60 seconds. Then, add the supernatant into the boiling test tube and repeat this step one more time with another 1 mL of deionized water. Acquire a pair of metal test tube holders and heat the boiling test tube to evaporate the water for 15 minutes. Let is cool after and weigh it. Then, calculate a percent yield of zinc iodide and write a balanced chemical equation and determine the limiting
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.
To get mass of food burnt, I subtracted the initial mass by the final mass. I then repeated these steps for the other two samples making sure to clean and dry the beaker each time. I got the heat energy gained by multiplying the ΔT by the mass of the water and 4.184 J/g°C. Then I calculated the heat energy per unit mass by taking my heat energy gained and dividing it by the mass of food burnt to get Joules/ g. To get the Cal of the sample I took the J/g and divided it by 4.184 and then divided that answer by 1,000 to get my Calorie. Observations: Marshmallow: I noticed that the marshmallow caught fire pretty quick.
Then, 3.4 g of ammonium sulfate was slowly added to the supernatant 1 as it was stirred for 15 min to achieve 50% saturation (85g/L of solution). The supernatant was then centrifuged at 9000 x g and 40C for 15 min and 5 ml of the second supernatant was transferred to a conical tube. The obtained second pellet was resuspended in 4 ml of distilled water and transferred into another dialysis
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
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.
100. g Al reacts with excess O2 to produce 150. g Al2O3 according to Calculate the theoretical and percentage yield. 4Al + 302 → 2 Al2O3. 79.4 % 14. Calculate the energy produced by the complete reaction of 150. g H2. 2H2 + O2 → 2H2O + 130KJ 4.83 x 103 kJ 15.
In part C of the experiment, we were to demonstrate osmosis between distilled water and each of the solutions in the dialysis tubes (water, 0.2 M, 0.6 M, 0.8 M, and 1.0 M sucrose all represented by unknown colors). We hypothesized that all of the dialysis bags except water will increase in mass. This is because the bags will be hypertonic to the distilled water solution in the beaker, meaning that there are more solutes and less water than the surrounding. In a hypertonic condition, water is rushed into the cell (or the dialysis tube in this case) in order to dilute the concentrated solution in the cell. Water would not change in mass because it is isotonic to its surrounding.
Diffusion on a liquid in a liquid: In this experiment I used three glasses filled with tap water. All three cups measured the same at 15 cm from the top to the bottom. I let the water settle, before I started the experiment. I then placed one drop of black food coloring into the first glass and waited for the coloring to reach the bottom. I calculated 96 seconds.