Record the mass of thyme used. 2. Using a measuring cylinder, add 50cm3 of 1.0mol dm-3 sulphuric(VI) acid and boil gently for 5 minutes. 3. Allow the mixture to cool for a few minutes then filter it, using either gravity or vacuum filtration.
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. Place another dry test tube in a 50mL beaker and weigh it. Find a bottle of barium iodide and record the name and molar mass. Then, weight out either anhydrous barium iodide or barium iodide dehydrate into this test tube and dissolve is it in 2 mL of deionized water. Pour the contents of one of the test tubes into the other and a reaction should occur and you should see a white precipitate of barium sulfate form.
Using another 125-mL flask, 60-mL of 0.3622 M potassium hydroxide in ethanol was deposited. Both flasks were clamped in a temperature-controlled bath regulated at 50.0˚C. The solutions were then set in the temperature bath for ten minutes to equilibrate. An empty 250-mL Erlenmeyer flask was also clamped in the same water bath. In another flask 50-mL of ice water was deposited with three-drop phenolphthalein.
The supernatant liquid was then decanted. 200 mL of hot deionized water then added to the beaker and again decanted to remove the excess NaNO3. Fourth, 15 mL of sulfuric acid (H2SO4) was added to the precipitate. The solution was being stirred during the reaction. The solution turned blue.
This is done by a procedure called refluxing. Refluxing is the process of heating a product to the boiling point and re-condensing the vapor continuously. The procedure halogenation is the addition of a halogen to a π bond forming a halo alkane. In this synthetic reaction bromine was used in the process called bromination. The bromine is acting first like an electrophile, and then after bromine has broken the π bond, a carbocation has formed, and a bromide ion has been created, the bromide ion then acts as the nucleophile and forms a bond with the carbocation.
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.
Now to begin, pour 50 mL of the sodium phosphate buffer solution with a pH of 6.84 into the 150 mL beaker. From here on out, the sodium phosphate buffer solution will be referred to as simply the buffer solution. Next, locate the indicator called bromothymol blue (0.04%) and add 20 drops to your 150 mL beaker. The solution should then appear green. Next, obtain a 5 mL serological pipet and thoroughly rinse it with the buffer solution, then discard the buffer solution into the 250 mL beaker.
b. Once again, place assembly in water bath and begin to heat c. When acetamide has begun to melt, record the temperature. d. Let assembly cool down and record temperature when acetamide begins to recrystallize. e. Repeat process two more times. Data: Data Table 1 | | | Rubbing Alcohol Trial # | Boiling Point | Percent Error | 1 | 79.5 C | 3.52% | 2 | 84.0 C | 1.90% | 3 | 83.5 C | 1.30% | Data Table 2 | | | | Acetamide Trial # | Melting Point | Freezing Point | Percent Error (Melting Point) | 1 | 79.5 C | 57.5 C | 3.50% | 2 | 80.5 C | 59.5 C | 0.60% | 3 | 78.0 C | 61.0 C | 3.70% | Observations: It was observed that thermometer placement could affect the readings in the water bath.
How it was expected the pH at equivalence point was 9.17 this is because of the domination of hydroxide ion in solution. The relationship between the pH and the amount of titrant added offered a better understanding of the equilibrium properties of the acid. Introduction Titrations are a convenient and common method of analysis. Generally titration is an experiment where a known property of one solution is used to infer an unknown property of another solution. There are several types of titrations: Acid-base titrations are based on the neutralization reaction between the analyte and an acidic or basic titrant.
Experiment 5: Preparation of Cyclohexene- Acid Catalyzed Elimination of Cyclohexanol Ball State University Organic Chemistry Lab 231 (Sec. 5) Dr. Bock/Daniel Miller Tiffany Raber 5 November 2012 Purpose: To prepare an alkene by an elimination reaction of an alcohol in the presence of sulfuric acid as a catalyst to produce a successful yield and desired results for the purity of the alkene. Introduction: The dehydration of an alcohol such as cyclohexanol is a useful technique for generating alkenes. The success of this reaction relies on a dehydration, such as the presence of a strong acid (sulfuric acid). Because this reaction is reversible, a fractional distillation is necessary to produce cyclohexene, water, and some impurities and a simple distillation is followed to further purify the product.