The Determination of the Properties of Acids and Bases Using the Acetic Acid and Sodium Acetate Buffer System
Purpose
The purpose of this experiment was to explore some of the properties of the acetic acid and sodium acetate buffer system, such as the greatest buffering capacity and the acid and base neutralization ability of several different concentrations of this buffer.
Reagents
The reagents used were the following: 0.10 M acetic acid, 0.010 M acetic acid, 0.60 M acetic acid, 0.60 M sodium acetate, 0.10 M sodium acetate, 0.010 M sodium acetate, 0.40 M HCl, 0.40 M NaOH, 10 mL H2O, 20 drops of thymol blue, and 10 drops of bromothymol blue.
Set Up
There were no unusual apparatus used in this experiment.
Reactions
C2H4O2(aq) + H2O(l) …show more content…
Data, Observation, and Results
Overall, the results of the experiment show that the buffering capacity increases as the concentration of the acetate buffer system (concentration of acetic acid and sodium acetate) increases. Tables 1 and 2 show values for the solutions (acetic acid and sodium acetate) that were made in week 1 of the experiment. They also state the precise concentration of the final solution based on the precise volume and concentration of the initial solution. Table 2 also shows the mass of sodium acetate added for the 0.60 M solution. Tables 3 and 4 show the results for week 2 of the experiment. They state the moles of NaOH or HCl needed to reach the orange or green endpoints for each concentration of buffer using the molarity of the acid or base and the number of mL needed to reach the …show more content…
The exact concentrations of the acetic acid solutions were 0.098 M and 0.0096 M. The exact concentrations of the sodium acetate solutions were 0.59 M, 0.097 M, 0.0095 M. In week 2 of the experiment, the following was determined: the effect of adding acid with no buffer present (Part A), the effect of adding acid to different concentrations of the acetate buffer system (Part B), and the effect of adding base to different concentrations of the acetate buffer system (Part C). All of the parts of the experiment showed that a higher concentration of the acetate buffer system had a higher buffering capacity. The 0.60 M concentrations of acetic acid and sodium acetate provided the greatest buffering capacity. This is because they resulted in the highest number of moles of HCl (0.0024) and NaOH (0.0028) needed to reach the endpoint for the experiment. This means that the greater the number of mL or moles needed to reach the endpoint, the greater the buffering capacity. This is because it signifies that the highest concentration buffer resist the most change in pH. If a student were to use the bromothymol blue indicator instead of the thymol blue indicator in Part B, he/she would not be able to test the buffering capacity of acetic acid/sodium acetate buffer by adding HCl because bromothymol blue changes color when the buffering
Purpose
The purpose of this experiment was to explore some of the properties of the acetic acid and sodium acetate buffer system, such as the greatest buffering capacity and the acid and base neutralization ability of several different concentrations of this buffer.
Reagents
The reagents used were the following: 0.10 M acetic acid, 0.010 M acetic acid, 0.60 M acetic acid, 0.60 M sodium acetate, 0.10 M sodium acetate, 0.010 M sodium acetate, 0.40 M HCl, 0.40 M NaOH, 10 mL H2O, 20 drops of thymol blue, and 10 drops of bromothymol blue.
Set Up
There were no unusual apparatus used in this experiment.
Reactions
C2H4O2(aq) + H2O(l) …show more content…
Data, Observation, and Results
Overall, the results of the experiment show that the buffering capacity increases as the concentration of the acetate buffer system (concentration of acetic acid and sodium acetate) increases. Tables 1 and 2 show values for the solutions (acetic acid and sodium acetate) that were made in week 1 of the experiment. They also state the precise concentration of the final solution based on the precise volume and concentration of the initial solution. Table 2 also shows the mass of sodium acetate added for the 0.60 M solution. Tables 3 and 4 show the results for week 2 of the experiment. They state the moles of NaOH or HCl needed to reach the orange or green endpoints for each concentration of buffer using the molarity of the acid or base and the number of mL needed to reach the …show more content…
The exact concentrations of the acetic acid solutions were 0.098 M and 0.0096 M. The exact concentrations of the sodium acetate solutions were 0.59 M, 0.097 M, 0.0095 M. In week 2 of the experiment, the following was determined: the effect of adding acid with no buffer present (Part A), the effect of adding acid to different concentrations of the acetate buffer system (Part B), and the effect of adding base to different concentrations of the acetate buffer system (Part C). All of the parts of the experiment showed that a higher concentration of the acetate buffer system had a higher buffering capacity. The 0.60 M concentrations of acetic acid and sodium acetate provided the greatest buffering capacity. This is because they resulted in the highest number of moles of HCl (0.0024) and NaOH (0.0028) needed to reach the endpoint for the experiment. This means that the greater the number of mL or moles needed to reach the endpoint, the greater the buffering capacity. This is because it signifies that the highest concentration buffer resist the most change in pH. If a student were to use the bromothymol blue indicator instead of the thymol blue indicator in Part B, he/she would not be able to test the buffering capacity of acetic acid/sodium acetate buffer by adding HCl because bromothymol blue changes color when the buffering