Acids And Buffers Lab Report

Acids, Bases, and Buffers
Introduction:
The pH scale is used to determine how acidic or basic a solution is, ranging from 1-14. The most acidic of all acids are at a pH level of 1 and the most basic of all bases are at 14. The neutral pH level is 7, which is what drinking water is. The pH level is determined by the amount of H+ ions present in a solution, and the more H+ ions there are the more acidic it is, and the lack of these ions results in more basic solutions. One distinguishing feature between acids and bases is that acids contain H+ ion and bases contain OH- ions. The reason why water is a neutral substance is because it has the same number of H+ (Hydrogen) ions as OH- (Hydroxide) ions.
H20⇔ H+ + OH- A buffer is a solution that
The acidic solution was 0.1M HCl and the basic solution was 0.1M NaOH, and the solutions that were tested are .1M NaCl, skim milk, .1M phosphate buffer, and water. Another thing that was need for this experiment were 8 test tubes, a pH sensor, distilled water, and dry sterile wipes. The first step was to begin with 10mL of each the solutions that were to be tested in the 8 test tubes, 2 tubes per each solution. Then the next step was to label the tubes with the proper names plus acid or base. Each of the solutions had one tube for name plus acid, and one tube for name plus base. After we labeled the tubes the next step was that the pH sensor had to be cleaned or the results could be contaminated, this step had to be repeated after each pH test. Using distilled water to rinse the sensor, and then use the wipes to dry it did this. After the sensor was clean, the initial pH level was tested. T he first test began with .1M NaCl and 0.1M HCL. After testing the initial pH level, 5 drops of the acidic solution were added and a new pH level was found (after the senor was cleaned). The data was recorded, the sensor cleaned and dried again, and then another 5 drops of 0.1M HCl were added. This process of adding solution, testing pH level, and cleaning sensor are repeated until 30 drops of 0.1M HCl have been added. After this, the base was tested in .1M NaCl. The sensor is cleaned and the initial pH level
This would show which materials acted better as buffers, for those with higher change in pH were not good buffers, and those with a lower change in pH were better buffers. With information from Table 1, four graphs were made, one for each material (0.1M NaCl, skim milk, 0.1M phosphate buffer, and DI water). Figure 1 was made to show how well 0.1M NaCl acted as a buffer in this experiment, which is known by how great the change is in pH level. The next graph, Figure 2, was made to show how well skim milk acted as a buffer. Figure 3 was made to show the change in pH of 0.1M phosphate buffer throughout the experiment, and Figure 4 shows the change in pH of DI water when