Ph and Buffers Lab

Buffers, and pH, and Diffusion oh my The pH of a solution is the measure of the concentration of charged Hydrogen ions in that given solution. A solution with a pH lower than seven is considered to be acidic. A solution with a higher pH is a base. It is very important for organisms to maintain a stable pH. Biological molecules such as proteins function only at a certain pH level and any changes in pH can result in them not functioning properly. To maintain these constant pH levels, buffer solutions are used. A buffer solution can resist change to small additions of acids or base’s. A good buffer will have components that act like a base, and components that act like an acid. Diffusion is random movement of molecules or other particles, resulting in even distribution of particles when no barriers are present (David Sadava, 2011). Diffusion always occurs from areas of high concentration to areas of low concentration, and leads to uniform distribution of solutes. Molecular weight plays a large role in diffusion. The first experiment we did was to simply test the pH of white grape juice, 7-Up, white wine, seltzer water, milk of magnesia, sodium bicarbonate, and Maalox. We hypothesized that the white grape juice, 7-Up, white wine, and seltzer water would be acidic while the others would be basic. This is because I know that the more acidic 7-Up and white grape juice have been known to rot and corrode teeth. The second experiment we conducted was to test for chloride ions and starch. We did this by adding drops of silver nitrate and iodine to Sodium Chloride, starch and distilled water. Our hypothesis for this experiment was that the silver nitrate would react in some way with the sodium chloride and the starch, but not with the water. The third experiment we conducted was to test the buffer zone of a buffer solution. We used a 2 pH buffer solution and steadily added hydrochloric acid, then sodium hydroxide as a base. Our hypothesis was that we would reach

Bibliography: David Sadava, D. M. (2011). Life: The Study of Biology Ninth Edition. Saunderland: Planet Friendly Publishing. Jacobs, C. W. (1998). Diffusion and Osmosis. Retrieved from Henry Ford Community College: http://sciweb.hfcc.net/Biology/jacobs/bio131/diffusion/Diff&Os.html