To the second, add 10% NaOH dropwise until the pH is 14. (To do this, add a couple of drops of NaOH to the tube; stir thoroughly with a stirring rod; then touch the stirring rod to a piece of pH paper to check your pH.) To the third, add 0.5% sodium bicarbonate solution to pH 9, and to the fourth, add 2% HCl to pH 2. Record your observations on the data sheet. Repeat the above tests using 2% casein solution.
Another source of rennin is junket tablets, which are used in setting milk into a solid junket or dessert. Junket tablets are used as a source of rennin in this experiment. Materials (per group) (This experiment may be done in groups of four. Each student can look after two temperature set-ups.) » 2 Bunsen burners »2 tripods » 2 wire gauzes » 2 × 150 mL beakers » 2 × 250 mL beakers for 70°C and 80°C water baths » 5 Styrofoam cups for unheated water baths » 8 thermometers 0–100°C » 16 test tubes in a rack » 10 mL measuring cylinder » junket tablet » 50 mL milk » Crushed ice » dropper » plastic spoon » marking pen » Distilled water Note: Thermostatically controlled water baths may be used if available.
In this experiment, we were trying to determine which organic molecules were present in three different unknown protein dietary supplements, and if they were or were not mainly protein based, or if they contained other molecules as well. Many dietary supplements simply claim to be full of proteins, but are they really? In this experiment, we hope to determine if this is true or not. In order to determine the organic molecules present in each of the different unknown dietary supplements, we used four reagents: Lugols, Benedict’s, Ninhydrin, and Biuret. We each chose one of the reagents and ran three different trials for each reagent.
3. Make three sets of the six test tubes and place a couple in the three different beakers 4. Place test tube 1 and 2 in the beaker that has a temperature of 0-10degrees. 5. Place test tube 3 and 4 in the beaker that has a temperature of 35-40degrees.
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.
Materials & Methods Identifying the unknown compound solution (#2314) first required the identification of each individual solution. One drop of each solution was added to five individual wells of a spot plate. Next, three drops of 3M hydrochloric acid (to be referred to from now on as HCl). The spot plate was then cleaned, and the procedure above was recreated two more times, the second test done by adding 3M ammonium hydroxide (NH4OH), and the third by adding 1 drop of dimethylglyoxime (DMG). All color observations were recorded and compared to the known behaviors of the focus metals.
Next, we put starch solution and a couple drops of iodine into a reaction tube, and recorded the color. We then got another reaction tube, put starch solution and saliva in it, and then put it underwater in a machine for 30 minutes. After the 30 minutes, we removed the tubes from the machine and added a couple drops of iodine to the solution. Lastly, we compared the colors of the two solutions to each other. Sweetness perception is the ability to taste sweetness.
4. Next, the biochemical reactions tests are performed. Inoculated three Durham tubes of phenol red broth with unknown bacteria, each containing a carbohydrate- sucrose, glucose, and lactose as a substrate. Incubated at 37 degrees for 24 hrs. Colorimetric changes are used to observe fermentation and bubbles tube to check for gas.
The last two cations should be separated with the observations of the additional NH4OH added. With that all the cations are separated, a confirmation test was given to all the cations. 20 drops of each cation solution were placed in new centrifuge tubes. A Bunsen burner was set up with a sharp blue cone that was inside of the flame, then a Nichrome loop was dipped into HCl then dipped into one of the cation
INTRODUCTION: This experiment aims to demonstrate liquid-liquid extraction. Chemicals used were 18.0 M Acetic Acid, Toluene, Phenolphthalein and 0.1M Sodium Hydroxide. In this experiment, the process of titration was used in order to determine the amount of acetic acid, which was done in three different procedures (1 trial each). The calculations took place right after accomplishing all