How Effective is the Antacid?

Introduction
When acid and base react together they produce water and salt (Bauer, et al). Acids are often known as hydrogen H (+) donors and bases are hydrogen acceptors. For example, the reactions observed in this lab were:
Equation 1, Part 2 (Bauer, et al)
NaOH (aq) + KHP (aq) Na+(aq) +KP- (aq) + H2O (l)
Equation 2,Part 3 (Bauer, et al)
HCl (aq) + NaOH (aq)H2O (l) + NaCl (s)
Where for the first reaction, NaOH is the base and KHP is the acid; for the second reaction, NaOH is the base and HCl is the acid.
This lab presented the problem of determining the concentration of an solution of NaOH. The method used to achieve this goal was titration, which involves adding a substance with a known concentration to the substance with an unknown concentration,  until the solution reaches equilibrium (where the moles of the acid are equal to the moles of base) (Bauer, et al). The indicator phenolphthalein, which is clear in acidic solutions but pink in basic, is used as a clear determinant of when the solution reaches the endpoint of the reaction. The endpoint is the point in a titration reaction where the moles of acid are equal to the moles of base, so becomes easy to calculate the concentration of the unknown substance.
The real-world application of titration was evident in part three of the lab, because it was used to determine the concentration of base in various antacids that are commonly used. Through titration, the lab groups determined which brand of antacid  had the greatest amount of moles of base, and was therefore the most effective in neutralizing the acid.
Experimental
Part One:
For the first part of this lab, three (3) red litmus papers, three (3) blue litmus papers, a pH meter, and a bottle of universal indicator were collected as different methods to test for a solutions pH. Then, one 100ml beaker was filled with 50mL of vinegar, another with 50mL of tap water, and the last with a 50mL of deionized water with a small scoop of baking soda dissolved into it. These three solutions were meant to display a range of pH; the vinegar (acetic acid) is an acid, the baking soda solution is a base, and the tap water was meant to be neutral.
Then, the pH of each solution was tested using a range of methods. The red and blue litmus paper were first dipped into each solution separately and allowed to change color, which was recorded into table 1. The pH meter was used next, but it first had to be calibrated to ensure accuracy. The pH meter was calibrated through the labquest software, using a sample of a known pH of 4 and a sample of a known pH of 10 to provide a range of pH’s to sense. Once the pH meter was calibrated, the pH of the vinegar, baking soda solution, and deionized water was determined by dipping the pH probe into the solution and waiting for the pH meter to read an accurate number and recorded into table 1 as well. The pH probe was cleaned with DI water in between uses to prevent contamination.
The last pH test performed was the color change caused by universal indicator. Three (3) drops of universal indicator was added to each of the three (3) solutions and the beakers slightly stirred. Once the color change was complete, the colors of each of the solutions was recorded into table 1 and compared to a chart provided which described which colors were associated with which pH, and this was also recorded.

Section 2
For the second section of this lab, a burette, hot plate, stir rod, and 250 mL Erlenmeyer flask were collected in order to run a titration using three (3) samples of 1.3 – 1.5g of potassium hydrogen phthalate (KHP) and 100 mL of sodium hydroxide (NaOH) and 3 drops of phenolphthalein. The buret was cleaned and primed by adding 5 ml of NaOH onto the buret and allowing it to flow through. Then, the remaining NaOH was added to the burette until it reached the 0mL mark. Then, the burette was placed on its stand and positioned above the hot plate. Then, the sample of KHP was placed into a 250mL erlenmeyer flask along with 50 mL of DI water. A stir bar was placed into the solution, and then that solution was placed on top of a hot plate. The stir bar was activated by the hot plate mixed the solution until the KHP was fully dissolved. After this step, three (3) drops of phenolphthalein were added to the flask as well. Then, the burette was opened slightly so that NaOH could fall into the flask drop by drop while the stir bar spun. This was allowed to continue until the solution turned light pink, at which time the burette was closed and its final buret measurement of NaOH was collected. This data was added into data table 2. The flask was cleaned and then set up again precisely as before, for two more trials. The starting and ending measurements of NaOH in the burette were recorded into table 2 as well, so a total change in volume could be calculated.

Section 3
For the third section of this lab, again a burette, hot plate, stir rod, and 250 mL Erlenmeyer flask were collected in order to run a titration using six (6) Bayer brand Alka-Seltzer tablets, 60 mL of 1.5M hydrochloric acid (HCl) and 100 mL of unknown concentration of sodium hydroxide (NaOH) and 3 drops of phenolphthalein. The buret was again cleaned and primed by adding 5 ml of NaOH onto the buret and allowing it to flow through. Then, the remaining NaOH was added to the burette until it reached the 0mL mark. Then, the burette was placed on its stand and positioned above the hot plate. Then, two (2) alka-seltzer tablets were weighed, recorded into table 3, and placed into a 250mL erlenmeyer flask. 50 mL of distilled water was then added into the flask and stirred until the antacid was dissolved completely and stopped bubbling. Then, 20 mL of 1.5M HCl was added to the flask and allowed to react with the solution. The flask was gently stirred until it stopped bubbling. At this point the flask was given a stir bar and three (3) drops of phenolphthalein. The flask was placed onto the hot plate, positioned under the burette. Then, the burette was opened slightly so that NaOH could fall into the flask drop by drop while the stir bar spun. This was allowed to continue until the solution turned light pink, at which time the burette was closed and its final buret measurement of NaOH was collected. This data was added into data table 3. The flask was cleaned and then set up again precisely as before, for two more trials. The starting and ending measurements of NaOH in the burette were recorded into table 3 as well, so a total change in volume could be calculated.

How Effective is the Antacid?

Introduction
When acid and base react together they produce water and salt (Bauer, et al). Acids are often known as hydrogen H (+) donors and bases are hydrogen acceptors. For example, the reactions observed in this lab were:
Equation 1, Part 2 (Bauer, et al)
NaOH (aq) + KHP (aq) Na+(aq) +KP- (aq) + H2O (l)
Equation 2,Part 3 (Bauer, et al)
HCl (aq) + NaOH (aq)H2O (l) + NaCl (s)
Where for the first reaction, NaOH is the base and KHP is the acid; for the second reaction, NaOH is the base and HCl is the acid.
This lab presented the problem of determining the concentration of an solution of NaOH. The method used to achieve this goal was titration, which involves adding a substance with a known concentration to the substance with an unknown concentration,  until the solution reaches equilibrium (where the moles of the acid are equal to the moles of base) (Bauer, et al). The indicator phenolphthalein, which is clear in acidic solutions but pink in basic, is used as a clear determinant of when the solution reaches the endpoint of the reaction. The endpoint is the point in a titration reaction where the moles of acid are equal to the moles of base, so becomes easy to calculate the concentration of the unknown substance.
The real-world application of titration was evident in part three of the lab, because it was used to determine the concentration of base in various antacids that are commonly used. Through titration, the lab groups determined which brand of antacid  had the greatest amount of moles of base, and was therefore the most effective in neutralizing the acid.
Experimental
Part One:
For the first part of this lab, three (3) red litmus papers, three (3) blue litmus papers, a pH meter, and a bottle of universal indicator were collected as different methods to test for a solutions pH. Then, one 100ml beaker was filled with 50mL of vinegar, another with 50mL of tap water, and the last with a 50mL of deionized water with a small scoop of baking soda dissolved into it. These three solutions were meant to display a range of pH; the vinegar (acetic acid) is an acid, the baking soda solution is a base, and the tap water was meant to be neutral.
Then, the pH of each solution was tested using a range of methods. The red and blue litmus paper were first dipped into each solution separately and allowed to change color, which was recorded into table 1. The pH meter was used next, but it first had to be calibrated to ensure accuracy. The pH meter was calibrated through the labquest software, using a sample of a known pH of 4 and a sample of a known pH of 10 to provide a range of pH’s to sense. Once the pH meter was calibrated, the pH of the vinegar, baking soda solution, and deionized water was determined by dipping the pH probe into the solution and waiting for the pH meter to read an accurate number and recorded into table 1 as well. The pH probe was cleaned with DI water in between uses to prevent contamination.
The last pH test performed was the color change caused by universal indicator. Three (3) drops of universal indicator was added to each of the three (3) solutions and the beakers slightly stirred. Once the color change was complete, the colors of each of the solutions was recorded into table 1 and compared to a chart provided which described which colors were associated with which pH, and this was also recorded.

Section 2
For the second section of this lab, a burette, hot plate, stir rod, and 250 mL Erlenmeyer flask were collected in order to run a titration using three (3) samples of 1.3 – 1.5g of potassium hydrogen phthalate (KHP) and 100 mL of sodium hydroxide (NaOH) and 3 drops of phenolphthalein. The buret was cleaned and primed by adding 5 ml of NaOH onto the buret and allowing it to flow through. Then, the remaining NaOH was added to the burette until it reached the 0mL mark. Then, the burette was placed on its stand and positioned above the hot plate. Then, the sample of KHP was placed into a 250mL erlenmeyer flask along with 50 mL of DI water. A stir bar was placed into the solution, and then that solution was placed on top of a hot plate. The stir bar was activated by the hot plate mixed the solution until the KHP was fully dissolved. After this step, three (3) drops of phenolphthalein were added to the flask as well. Then, the burette was opened slightly so that NaOH could fall into the flask drop by drop while the stir bar spun. This was allowed to continue until the solution turned light pink, at which time the burette was closed and its final buret measurement of NaOH was collected. This data was added into data table 2. The flask was cleaned and then set up again precisely as before, for two more trials. The starting and ending measurements of NaOH in the burette were recorded into table 2 as well, so a total change in volume could be calculated.

Section 3
For the third section of this lab, again a burette, hot plate, stir rod, and 250 mL Erlenmeyer flask were collected in order to run a titration using six (6) Bayer brand Alka-Seltzer tablets, 60 mL of 1.5M hydrochloric acid (HCl) and 100 mL of unknown concentration of sodium hydroxide (NaOH) and 3 drops of phenolphthalein. The buret was again cleaned and primed by adding 5 ml of NaOH onto the buret and allowing it to flow through. Then, the remaining NaOH was added to the burette until it reached the 0mL mark. Then, the burette was placed on its stand and positioned above the hot plate. Then, two (2) alka-seltzer tablets were weighed, recorded into table 3, and placed into a 250mL erlenmeyer flask. 50 mL of distilled water was then added into the flask and stirred until the antacid was dissolved completely and stopped bubbling. Then, 20 mL of 1.5M HCl was added to the flask and allowed to react with the solution. The flask was gently stirred until it stopped bubbling. At this point the flask was given a stir bar and three (3) drops of phenolphthalein. The flask was placed onto the hot plate, positioned under the burette. Then, the burette was opened slightly so that NaOH could fall into the flask drop by drop while the stir bar spun. This was allowed to continue until the solution turned light pink, at which time the burette was closed and its final buret measurement of NaOH was collected. This data was added into data table 3. The flask was cleaned and then set up again precisely as before, for two more trials. The starting and ending measurements of NaOH in the burette were recorded into table 3 as well, so a total change in volume could be calculated.