We then added 10cm3 ethanoic anhydride to the salicylic acid and swirled the contents, this mixes together the two chemicals. We then added 5 drops of concentrated sulphuric acid to the flask and thoroughly swirled the mixture, this creates the solution that makes the aspirin. We then warmed the flask for 20 minutes in a 400cm3 beaker of hot water which was approximately 60°C, we made sure the flask did not go above 65°C because this could have caused the contents to evaporate. Part 2: Using a 25cm3 measuring cylinder we measured out 15cm3 of ethanol into a boiling tube and then prepared a beaker half filled with hot water at approx. 75°C, we got this temperature by filling the beaker with cold water and slowly adding boiling water from a kettle until we reached the right temperature.
1 “substrate” and another “ enzyme.” Instead of using the distilled water, this time you are going to use different pH buffer in the enzyme test tube. In the substrate tube, add 7 mL of distilled water, 0.3 mL of hydrogen peroxide, and 0.2 mL of guaiacol for a total volume of 7.5 mL. For the enzyme tube, instead of distilled water add the pH solution (3) and 1.5 mL of peroxidase which equals a total volume of 7.5 mL. Use the dH2O syringe for our pH solution. To clean the syringe, flush it by drawing 6 mL of distilled water.
In the Oxidative fermentation tube the media was a differential media that helps determine whether specific bacteria can oxidize or ferment to metabolize glucose. Citrate test checks to see which bacteria could citrate as the only source of carbon. A positive test shows that an alkaline environment ia created and that the pH level rose. The color of the media changed from green to blue if its positive. The Bile Esculin agar test has its medium as selective and differential.
With the perfect conditions water boils at “212°F: Full rolling boil.”(Lopez,K) Another factor in boiling point is any impurities residing the the water itself. “For instance, if water comes to a boil at exactly 100 degrees Celsius at 1 atmosphere, it means that is pure and does not contain any impurities. If the boiling point differs, it must mean that the water is impure.”(Factors that affect the boiling point of water.) Overall there are many ways that water 's boiling point can be affected by outside forces, but the focus will be on alkaseltzer tablets and how they influence water 's boiling point. The active ingredients in the alka seltzer tablet are “As the tablets dissolve, the sodium bicarbonate splits apart to form sodium and bicarbonate ions.
Titration curve of NaCl and an unknown amino acid titrated with 2M HCl (blue), along with the NaCl blank (red). The graph shows the exact amount of HCl added in ml and the decrease of pH recorded during the titration. Figure 2: Titration curve of NaCl and an unknown amino acid titrated with 2M NaOH (blue), along with the NaCl titration with 2 M NaOH (red). The graph shows the exact amount of NaOH added in ml and the increase of pH recorded during the titration. It also shows that the same amount of NaCl base was used to titrate the blank.
Celery started with a pH of 6.05 and dropped down to a pH of 5.03 after 30 drops that is not nearly as drastic as alka seltzer. But, it shows how celery does not have a buffer because of the drop in pH and is not able to create more hydroxide ions when acid is added. Liver started with a pH of 6.50 and after 30 drops the pH dropped down to 6.03 which means the drop in pH is only .47 and looks similar to the data of the positive control of alka seltzer. The data in this lab follows the hypothesis of testing the HCI of liver and celery, then liver will contain a buffer and celery will not. This conclusion can be drawn because of celery’s large drop in pH and the data’s resemblance to the water data meaning celery cannot hydrolyze ions and keep a constant pH.
The time it takes for the reaction mix to turn blue will be measured with a stopwatch. For the procedure, you will vary the amount of hydrogen peroxide to see how this affects the time the mixed chemicals stay clear before turning blue. The reactions that form the basis for the iodine clock reaction are shown below. Equation 1: H2O2 + 3 I- + 2 H+ → I3- + 2 H2O • H2O2 = Hydrogen peroxide • I- = Iodide ion (from potassium iodide) • H+ = A proton, from hydrochloric acid (HCL) • I3- = Triiodide • H2O = Water Equation
When carbon dioxide reacts with water, carbonic acid is made. This 0.1% aqueous bromothymol blue solution (also known as Bromthymol Blue) is a commonly used pH indicator. Bromthymol blue changes color over a pH range from 6.0 (yellow) to 7.6 (blue). It is a good indicator of dissolved carbon dioxide (CO2) and other weakly acidic solutions. Despite its name, bromothymol blue solution may sometimes appear yellow or reddish depending on the pH of the stock water used to prepare this pH indicator solution.Low levels of carbon dioxide or acid in solution with bromothymol blue indicator will appear blue.