Ph and Buffer Solution

In this lab, the purpose was to determine the stability of a substance after adding an acid or a base. The results claim that liver and buffer are the most resistance to change in pH. Looking at figure 3, buffer and liver both maintain a stable pH even with the addition of an acid or base. However, potato and water have less buffer in them since their pHs did change. In figure 3, the potato acid’s pH level decreased by two, and the potato base’s pH level increased by two. The level of pH of a water acid decreased by 4, while the water base’s pH increased by 5. These results all tie to the fact that buffer is a substance that maintains a stable pH; the presence of buffer in organisms help maintain homeostasis by binding or releasing hydrogen

Tables 2,3,4,5 and 6 show that as duration increased the absorbance also increased for each pH. The solution in the conical flask became darker (yellow) in time this is because the substrate, p-nitrophenyl phosphate was catalysed by acid phosphatase, releasing Nitrophenolate anion. It was the Nitrophenolate anion giving off the yellow colour; the presence of this feature increases the absorbance rate. The addition of sodium hydroxide distorted the shape of the enzyme making it no longer effective in its function.

For part B, 50 mL of an assigned 50 mL pH solution of either 1 M HCl, 1 M NaOH, lemon juice, and 50 mL of household bleach all in separate 250 mL beakers are to be used. For part C, a hot plate or ice are to be used to make the 1.0 mL assigned temperature specific water. This experiment will also use the 1.0 mL of 0.1 Phosphate buffer.

A. How did the experiment in Part I demonstrate surface tension? Use your experiment observations when answering this question.

pH was recorded every time 1.00 mL of NaOH was added to beaker. When the amount of NaOH added to the beaker was about 5.00 mL away from the expected end point, NaOH was added very slowly. Approximately 0.20 mL of NaOH was added until the pH made a jump. The pH was recorded until it reached ~12. This was repeated two more times. The pKa of each trial are determined using the graphs made on excel.

will have a pH between 1 and 6 and the weak bases between 8 and 14. The exact order of weak acids and weak bases is determined by comparing the ionization constants (Ka for the weak acids and Kb for the

To improve the results from the experiment buffer solutions that were not whole pHs could have been used e.g. pH 4.5, 5.5 etc. This would have provided more reliable results as a wider range of results would have been produced. Using pHs with decimals would also help to more accurately determine the optimum pH as the optimum may have been above or below the pH stated in the hypothesis; 8. In this experiment however the optimum is taken at 8 because the graph does not rise again.

To make the buffer solution you need 0.2 mol dm-3 of Na2HPO4 and 0.1mol dm-3 of citric acid this will give 100cm3 of buffer. Here is how to get the different pH in the buffer solutions:

In this experiment different pH levels ranging from 3 to 11 were used to test the effects on daphnia heart rate. The pH scale ranges from 0 to 14. A pH ranging from 0 to 6 is acidic, a pH of 7 is neutral, and a pH higher than 7 ranging from 8 to 14 is basic. PH revolves around hydrogen ions (H+). The reason pH levels can be acidic, basic, or neutral is because acids give hydrogen ions away while bases accept hydrogen ions. (Decelles, 2002).

The Effect of pH on the Digestion of Casein by Trypsin When planning the experiment, the equipment and method had to be well thought-out in order for the experiment to be accurate and efficient. Firstly, I have chose to use a 1% trypsin concentration then altered it to 0.8%, because a higher concentration means more trypsin molecules in the solution and therefore more enzyme substrate complexes are likely to occur with the casein in the milk, causing digestion of the casein to be faster. However, I don’t wantowever digestion to occur too quickly as I will not be able to analyse the effect of PH. Therefore, I chose a lower concentration which would allow me to test the percentage transmission at

Why does the blood pH value change as PCO2 changes? Because the PCO2 is directly proportional to the H+ levels which are inversely proportional to the pH level of the blood.

Using Graph 1: The Volume of Titrant Added in order to reach the Endpoint and the Corresponding pH Values, observe the vertical line of each titration and see the points in which the horizontal lines intersect it. These points give the

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.

First, three titration curves and three second derivative curves were created to determine the average pH at the half-equivalence point from the acetic acid titrations. Titration curves were used as visuals to portray buffer capacity. The graphs and a table, Table 1, that showcased the values collected were created and included below. The flat region, the middle part, of Figures 1, 2 and 3, showed the zone at which the addition of a base or acid did not cause changes in pH. Once surpassed, the pH increased rapidly when a small amount of base, NaOH, was added to the buffer solution. Using the figures below and

In this lab a acid-base indicator phenolphthalein was used to determine endpoint of a reaction HCl(aq) and KOH(aq). At the end point all of the HCl(aq) would have reacted with KOH(aq), and the pH becomes 7. The phenolphthalein would changed colours from colourless to pink indication when enough KOH(aq) was added. The purpose of numerous trials was to use the average volume of the 3 trials with similar measurements.