PH

1000Watt, frequency 25 kHz and probe diameter of 13mm. Pectin solutions were treated at 60% duty cycles, sonication times was fixed at 20 minutes, sonication power (200 and 400 watts). Effect of acidity on sonication was determined at pH 2, 4 and 6, by adjusting solution pH using acetic acid. Native pectin 0.25g was put in 250ml beaker suspended in 100ml deionized water to achieve low viscosity, it was stirred on a magnetic stirrer for 30 minutes, and sonic treatment was done by immersing sonic probe

performed to determine the equivalent mass and dissociation constant of an unknown weak monoprotic acid. For a monoprotic acid, it is known that pH = pKa + log (Base/Acid). When a solution has the same amount of conjugate base and bronsted lowry acid, log (Base/Acid) = 0 and pH = pKa. By recording the pH value throughout the titration process and determining the pH at half- equivalence point, the value of Ka can be easily calculated. In this experiment, the standardized NaOH solution has a concentration

vegetation) and limnetic (area too deep to support rooted vegetation) zones in the pond. In the littoral zone three groups collected data on water temperature, pH, water depth and biota. Sampling was done along three transects, where samples were taken at 1,2,3 and 4 meters from shore. Water pH was measured using standard pH paper as well as an electronic pH meter. Water temperature was measured using a thermometer. Water depth was physically measured. Biota data included the percentage of vegetative coverage

As mention above citric acid act to neutralize the solution through reaction (2) as a result, the pH of the reaction solution decreases with increasing concentration of citric acid. If the concentration of citric acid citrate exceeds 1:2, the solution pH is lower than 8 and citrate anions also inhibit the nucleation and growth of CuO crystals. It was concluded that the gel specifications were changed by varying the amount of

and Procedures Materials: - Turnip peroxidase (4%) - 0.1% hydrogen peroxide - 0.3% guaiacol - Distilled Water - 12 test tubes and a test tube rack - Timer - 1,5, and 10 mL syringes - 6 Cuvettes (approx. 16x150 mm) - Test tube cleaning sheet - pH 3,5,6,7,8 and 10 - Spectrophotometer - Funnel -Safety goggles (Safety precautions are listed in the procedures.) Procedure 1: Step 1-Make a blank using 13.3 mL of distilled water, .2 mL of guaiacol, and 1.5 mL of enzyme extract. Then pour the

equimolar concentration at pH 7.4 where A1-40 carries a net charge of -2.9 (Fig 2b). A decrease in the buffer pH from 7.4 to 2.5 reduces the electrostatic interaction between PMA and A1-40 (net charge +6.7) and resulted a random coil A1-40 conformation (Fig 2b, red graphs). Moreover, we observed -helical CD spectra for A1-40 interacting to DMPC nanodiscs at pH=5.5 where A1-40 nearly carries no charge (Fig 2b). Overall the CD results suggested that at physiological pH, the cationic PMA binds strongly

decrease in the ocean’s pH is called ocean acidification. The pH of ocean water has dropped because of humans releasing carbon dioxide into the air. The ocean absorbs about a third of the carbon dioxide released by human activity. The absorption of carbon dioxide leads to changes in the chemistry of the sea water which causes it to becomes more acidic. Seawater generally has a slightly basic pH of 8.2, but in the past two hundred years, it has increased by 0.1 units to an 8.1 pH. The decrease of the

Task 1: a) Acids and bases play a large and important role in our body through various biological processes. After a human being consumes food, the food gets transported to the stomach where the border cells located there start producing Hydrochloric Acid (HCl) which is an acid that aids in the digestion of the food. In order to buffer or neutralize this highly-acidic chemical, those same border cells also secrete a base called Sodium Bicarbonate (NaHCO3) at the same time thanks to their dual function

acidity in a particular substance a pH test is completed. The term pH stands for potential hydrogen, measuring how acidic or basic a substance is. Acids which have a higher concentration of H+ ions have a pH of less than 7; however, bases which have a lower concentration of H+ ions have a pH greater than 7. The pH of a substance is essential to understanding whether organisms can or cannot survive in a certain environment. For example sweet potatoes optimal pH range for growing is between 5.0-5.5;

reaction take less time because of the enzyme in the raw liver. 4). Materials Safety Goggles, 50 mL granulated cylinder, 10 mL granulated cylinder, glass vial with stopper and pipet, thermometer, plastic shoe box (tub), catalase from chicken liver, pH paper 0.1M NaOH, 3% Hydrogen Peroxide, tweezers, filter paper disks. 5). Procedure Fill bin with water Fill granulated cylinder with water by submerging and make sure no bubbles at the top. Place filter paper disks dipped in catalase on one side of