Procedure
- Put on safety goggles.
- Gathered the tools and ingredients needed to perform the experiment.
- Calibrated the pH probe using the buffer solutions pH 2 and 11.
- Set up a graph and table on the program to record observations.
- Using the mortar and pestle grinded and measured 1g of Tums and calcium carbonate antacid.
- In two beakers, measured 30ml of water.
- Stirred in 1g of each antacid into two beakers filled with 30ml of water.
- Using the pH meter, recorded the pH of the Tums solution.
- While swirling the Tums solution, gradually added the drops of stomach acid using micro dropper. Counted the number of drops added. Continued to add and count drops of solution until it reached a pH of 2.0.
- Repeated steps 8 and 9 using the calcium carbonate solutions.
Observations
Qualitative/Quantitative Observations
As more stomach acid was added to each antacid, the color of the solution started to get darker. It is predictable that the liquid increased in quantity and a bigger beaker was needed to continue the experiment. As the stomach acid was added bubbles formed around the surface of the antacid solutions. The more acid added resulted in bigger bubbles, and louder fizzing that rise to the top. The antacids seem to react with the stomach acid just like a can of pop reacts after it is shaken up. . It was recorded that 68 ml of Tums and 95 ml of generic antacid with stomach acid solution was remaining after reaching a pH of 2. It was evident that as approximately 60 drops of acid was added the pH altered around 0.1 - 0.2 pH on average. Towards the end of experimenting each antacid, as the acid was added the pH would increase by 2 or 3 but it will instantaneously drop to 0.1 - 0.2 pH than the previous recorded pH.
Discussion
The observations in the lab portray that, in general, brand name antacids are more effective than generic brands. The Tums solution, the brand name antacid, reached a pH of 2 after 2400 drops of stomach acid was added. The Calcium Carbonate solution, the generic antacid reached a pH of approximately two after 1980 drops of stomach acid added. The generic acid was not as strong enough to last before the solution changed to a pH of 2. Whereas the brand name solution lasted longer, for 420 more drops than the generic brand before it transformed completely into gastric acid. The alteration of the antacids from a base to an acid was a very slow process. The results show that 20 – 200 drops only changed the pH by one number. The more drops of stomach acid added to the solution, the slower the pH of the antacid solutions decreased.
The Law of Conservation of Mass is depicted through the mixture of stomach acid and antacid solution. The Law of Conservation of Mass states that the total mass of the reactants is always equal to the total mass of the products. The Conservation of Mass can be evident in the Tums mixture. The Tums mixture consisted of one gram of antacid with 30 ml of water with 2400 drops of stomach acid. Since 60 drops is equivalent to 1 ml, 40ml of stomach was used to transform the Tums solution into gastric acid. The one gram Tums dissolves in the 30 ml of water mixed with 40 ml which resulted in the mass of approximately 70 ml. The recorded mass at the conclusion of the experiment was 68 which are relatively adjacent to 70 ml. It is possible that a few drops were discounted or spilled. The particular type of reaction involved in the lab is the neutralization reaction. The neutralization reaction involves the reaction of an acid and base to create some salt and water. An acid, the stomach acid (HCL) and the base, the antacids (CaCO3) react with each other to create a salt (CaCl) and somewhat water (HCO3). The hydrogen carbonate also known as bicarbonate is a base that is an important component of pH buffering system. The carbon dioxide that is contained in our body turns into carbonic acid which quickly turns into bicarbonate. The HCO3, in combination with water, hydrogen ions, and carbon dioxide forms buffering system. It is required to supply punctual resistance to severe pH changes in both acidic and base directions. The bicarbonate is partially water and it is used to decrease augmented acidity especially in the body. The reaction also shows the law of conservation of mass as the equation is balanced on both sides of the equation.
The ingredients in Tums include Sucrose, Calcium Carbonate, Corn Starch, Talc, Mineral Oil, Natural & Artificial Flavors, Adipic Acid, Sodium Polyphosphate, Red 40 Lake, Yellow 6 Lake, FD&C Yellow 5 Lake (Tartrazine), Blue 1 Lake. The ingredients in generic antacid include Calcium (as calcium carbonate), De-Glycyrrhizinated Licorice (root) 760 mg, and L-Glycine. The ingredients have selected ingredients like calcium carbonate, corn starch, talc, mineral oil and natural flavors help decrease the acidity of the stomach. The remaining ingredients are usually used for flavoring and color which are considered as bases so they may have a small part in neutralizing the stomach acid. The generic antacid contain three main ingredients which are meant to help the stomach acidic but they only play a small part in neutralizing the stomach acid. The main ingredient in both antacid that contributes to the neutralization of acid is calcium carbonate. The additional ingredients act as secondary ingredients that help stomach acidity. The brand name antacid contains more alkaline ingredients that last longer towards stomach acid. However the ingredients in the generic antacid appear to be less powerful against gastric acid although they do contribute to the neutralization process.
I would want an antacid to dissolve instantly because the faster the antacid dissolves the sooner the antacid will digest and contact the excess acid. If the antacid dissolved instantaneously, less time is spend for the antacid to neutralize the gastric acidity. If the antacid dissolves over a period over time it is not as effective because it will take days even weeks before the antacid neutralizes the acid in the stomach. The fast relief antacid is more in demand by consumers because it is not preferred to wait around for stomach pain relief. Many cases involve liquid medicines to contain more concentration than solid medicines. Liquid medicines are also easier to swallow; faster absorption rate and they are more natural. The solid medicines are preferred usually due to longer shelf life, better tasting (rather no taste) and more convenient for travel purposes. One another main variable that I would consider is the cost of the antacid. Although most antacids, whether name bran or generic, seem equally effective they have prices at long ends. If the antacid was meant for a child I would consider the flavor because some children are stubborn enough not to drink/swallow certain medicines because of the flavor of the antacid.
Evaluation
The lab procedure and the design of my experiment did contain some errors that could have been avoided to gather further accurate results. The first trial run of the antacid lab, our problem was the antacid read a pH of seven which was not significant. The factors that may have exaggerated the situation comprise of the pH probe or the mass of the reactants. The first trial, the group decided to choose a random mass of grounded antacid to dissolve in an unintentional amount of water. I think we should have really thought about the amount of water and antacid to dissolve together. A reduced amount of Tums or generic antacid and excess water may have been the reason that the pH probe was reading a pH of seven. The first time around the pH probe used by our group didn’t come with the little bottle at the end which means the bulb at the bottom of probe which measured the pH of the solution was not wet. The dry probe may have caused the antacid to have a ph of seven rather than a pH over seven. The number of mistakes made in the first time around supplied to the decision of the group to start fresh to record accurate results and improve the mistakes.
One of my biggest concerns was that it took around 2000 drops of stomach acid for the antacids to reach a pH of two. Whereas only 200 drops were required for the antacids to reach a pH of two for the additional groups. It also didn’t make sense that 1g of each antacid was strong enough to stand up to 2000 drops of stomach acid. The factors that could have affected the results include the mass of the reactants, the pH probe, the counting of drops or the stirring. The second time around we measured 1g of each grounded acid and 30 ml of water to be extra accurate. This helped the pH of both antacids to have a pH over seven. However it read that the antacids were weak considering the pH was only a little over a pH of seven. It didn’t make sense that the weak bases stood up to around 2000 drops of stomach acid. I think this time around the group may have measured 1g but added too much water that may have lengthened the process and the number of drops of stomach acid. In addition, the number of drops may have been discounted or we may have been counting too fast that we counted too many drops. The group decided to speed up the process, as we saw that the drops were not affecting antacids too much, we measured 60 drops to be equal to one pipette of solution. This resulted in us adding one pipette of stomach acid to each antacid considering it as 60 drops of stomach acid. The ‘pipette shortcut’ may have created inaccurate results and we may have calculated additional drops of stomach acid. Furthermore, the pH probe once again may have been collecting and recording approximate or incorrect results. It is also questionable that the washing of the probe before switching antacids may also have affected the number of drops that were counted. As the 50 ml beaker, filled with the antacid solution, started to fill up it was necessary to change to a 150 ml beaker. The alteration caused the 50ml beaker to have leftover antacid solution that was partially filled with stomach acid. The transformation from the 50ml beaker to the 150 ml beaker may have caused the increased number of drops. Lastly, a factor that was also an issue in the acid rain lab was the stirring portion of the lab. The pH of the antacid, after adding the acid, will alter depending on the stirring of the compound. If the solution is excellently stirred the pH would decrease so I think it would have helped to make sure, after each addition, to stir the solution properly.
The strengths of the lab included the pH probe program that recorded the quantitative observation. It was not necessary for our group to record the quantitative observations because the computer automatically recorded them, assuring accuracy. I also think that the same mass of materials for and of each antacid contributed to the accuracy of the results. The action to measure the same mass of each antacid, water and the same matter (powdering the antacids) was brilliant because there was no questioning at the end that one was proven stronger due to the mass or matter. The limitations of the lab were definitely the results of approximately 2000 drops of the stomach acid in order to alter the pH of the antacid to two. The results seemed inaccurate and unreasonable especially in comparison to the other groups. The above stated causes may have contributed to observations that were recorded by the pH program. Although it was helpful that the program recorded all the observations I was always doubtful if the starting pH was accurate especially due to the low starting pH for a base. I expected the pH of the antacid to be relatively close to 10 or 12 if it was capable to neutralize stomach acidity. The times that the pH was first put into the antacid, it was relatively close to the pH of 7 no matter of how powerful the antacid and it was amazing how many drops were needed to change a low base pH to a pH of 2.
Conclusion
It is evident through the results of the lab experiment that the brand name antacids are more effective than generic brands. The brand name antacid stood strong against the stomach acid until 2400 drops of stomach acid was added; however, the generic antacid was only able to withstand the stomach acid until 1980. The number of drops was relatively equivalent, in the long run, if the drops were rounded off to the nearest hundred. The Tums started off with a pH of 8.1, while the pH of the generic antacid was 7.5. This also proves that the Tums was a stronger base, to start off with, than the generic antacid. The physical properties of the chemical reaction were stated as the solution fizzed and bubbled as the stomach acid reacted with the antacids. There were also partial color changes occurring in the antacid solution and the stomach acid was added.
I hypothesized that the generic brand would be more effective due to the natural ingredients that the brand contained. However, it was proven through results of the lab that the brand name antacids were more effective. I thought that generic brand would be effective because it did not include the artificial flavor and coloring which I though would reduce the strength of the antacid.
Although results portray that the brand name antacids are more effective than the generic antacid, theoretically the two kinds of antacids are to be equally effective. The generic and the brand name antacids contain the same active ingredients. The only difference that the two kinds have are, the brand name antacid usually contain flavoring, coloring, and additional active ingredients. I think these extra ingredients in Tums, being mainly bases, may have contributed to gaining the name of the more effective antacid.
The antacid lab raised certain questions that remain in my mind that are left unanswered. I was wondering if the additional ingredients in the brand name antacid help to make the antacid stronger, if it makes the antacid weaker or if it has no effect on the antacid. I also wanted to know if the water added to antacids had any effect on the end results. A question that raised my mind was even though theoretically the brand name and the generic antacid are hypothetically equally operative why it is that consumers prefer the name brand, even after the low prices of the generic brand?
In reality, many people buy the brand name antacids because they are trusted by buyers and they are popular to consumers. I thought that the generic brand, although anonymous, they would be proven more effective and that consumers were making a mistake by buying the brand name just due to the fact that they were well-known due to advertising. I learned that brand name antacids are slightly stronger that generic and they are preferred because of the flavoring, color and even the shape. However, the lab taught me, on the long run they are both similarly effective because they have the same active ingredients. It is possible that one may be stronger than the other but they are both suitable for relieving pain for acidity in the stomach.
