Discussion
The acid neutralising capacity (ANC) of 3 brands of calcium carbonate (CaCO3) tablets was determined by reacting the tablets in excess standardized hydrochloric acid (HCl) and then back-titrating with a standardized sodium hydroxide (NaOH) solution. Back titration was required for two reasons. Firstly, CaCO3 tablets are poorly water-soluble but dissolve rapidly in acid. Secondly, CaCO3 is a weak base so it is difficult to determine the end point of the reaction if titrated directly.
Assuming good manufacturing practice, the amount of active ingredient described on the product label should conform to quality control standards and accurately reflect the experimentally determined content of CaCO3 in each tablet. Titralac antacid
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This is how effective the antacid is at neutralizing HCl (based on number of moles) relative to the tablet’s mass. A higher value for mass effectiveness is desirable. For Titralac the value was 11.8(mmol/g). This was greater than that of Tums with a value of 6.4(mmol/g). However, Quick-eze had the lowest mass effectiveness with a result of 3(mmol/g). Therefore Titralac would be the best choice although, Tums would be favoured over Quick-eze, a different result to that of cost effectiveness.
To mimic the action of the antacid being dissolved by stomach acid, the time taken for the tablets to react with 5-10 ml of HCl was assessed. This allowed for an indication of the speed of action of the tablets, which ranged from 3-6 mins. Titralac dissolved in 151 sec, Tums took 492 seconds and Quick-eze dissolved in 327 seconds. For a fair comparison the reaction time was corrected for the moles of CaCO3 in each tablet. In this case Titralac, Tums and Quick-eze were able to neutralise 3.45, 1.04 and 2.81mmol of acid per min respectively. Since the molarity of stomach acid is about 0.1M, this would neutralise about 10-30mL of stomach acid/min. Titralac therefore was marginally quicker than Quick-eze in neutralizing HCl, perhaps due to Titralac’s concentrated formulation giving it a small size and greater tablet surface area. In real life, the chewing of the tablets before swallowing may alter this brand difference.
A summary of the results is
1. To titrate a hydrochloric acid solution of “unknown” concentration with standardized 0.5M sodium hydroxide.
The goal of this experiment was to find out active chemical components in Anacin and Tylenol, using Thin Layer Chromatography technique. This technique uses the difference in the intermolecular forcer and polarity to separate mixtures. Comparing Rf values were then used to determine the active chemical components in the two analgesics. The overall result was that Acetaminophen exists in Tylenol and Acetylsalicylic Acid exists in Anacin.
Aspirin, Caffeine and Salicylamide were extracted from an over-the-counter pain reliever (BC Powder). These components were separated by manipulating their solubilities by adjusting the acidity and basicity of the solution. By doing this, the three components were forced into conjugate acid (or base) forms, causing selective solubility in either an aqueous or organic solvent. These layers were then separated by use of a separation funnel. Once separated, the components extracted were characterized by measuring the melting point and performing a TLC analysis. Also, the recovered aspirin from the first part of the experiment was recrystallized and compared to that of the
In experiment two, the drug Panacetin was separated by a series of chemical reactions into its three components: sucrose, aspirin, and an unknown active ingredient, either acetanilide or phenacetin. The purpose of this lab was to determine what percentages of each component is present in the pain-killer. The initial step was to dissolve Panacetin in dichloromethane. However, sucrose is insoluble in dichloromethane because organic molecules are soluble in organic solvents, and dichloromethane is an inorganic solvent, so only aspirin and the unknown dissolved. By using gravity filtration, sucrose was filtered from the solution and 0.30g of solid was collected.
Ever wonder about the chemical makeup of tablets that people take for pain relief? Before a tablet can be successfully made, the limiting and excess reactants must be considered. The limiting reactant will affect the amount of the product that can be made. Another reason why the starting reactants must be determined carefully is to make reduce the amount of the reactant in excess so that reactants are not wasted. This experiment uses an Alka-Seltzer tablet. Alka-Seltzer dissolves in water and is an antacid and a pain reliever1. The Alka-Seltzer tablet has many uses such as relief of headaches, ingestion, heart burns, or even upset stomachs2. The active ingredients in an Alka-Seltzer tablet is aspirin, also known as acetyl-salicylic acid (C8H12O4), citric acid (C6H8O7), and sodium bicarbonate (NaHCO3)2. The aspirin in the Alka-Seltzer tablet helps with pain relief. Because of the acid-base chemistry (Brønsted-Lowry), citric acid and sodium bicarbonate produce O2, which makes the tablet fizz when it is dropped in liquid. The Brønsted-Lowry theory shows how the Brønsted-Lowry acid donates a hydrogen ion while the Brønsted-Lowry base accepts the hydrogen ions3. The remaining NaHCO3 that is in excess post reaction with the citric acid is what is used to neutralize stomach acid which helps relief heart burn2. The problem in
The goal of this lab was to determine the amount of grams of sodium bicarbonate (NaHCO3) required to produce enough CO2 gas to completely fill the lab and also how many Alka-Seltzer tablets that would equate to. This was done by collecting CO2 gas by inverting a buret and submerging it under water in order to calculate the volume of CO2 released from a fragment of Alka-Seltzer tablet. The main component of Alka-Seltzer is sodium bicarbonate, used to neutralize excess stomach acid during illness through the following reaction that generates CO2:
The moment an Alka-Seltzer tablet hits water, it begins to fizz. These tablets are over-the-counter antacids and pain relief medications that contain aspirin, sodium bicarbonate, and citric acid. The fizzing is a result of a reaction occurring where carbon dioxide (in the form of bubbles), water, and sodium acetate is formed. The fizzing and carbon dioxide bubbles are a result of the sodium bicarbonate splitting and reacting with the citric acid. In this experiment we are determining the percent by mass of sodium bicarbonate (NaHCO3) in Alka-Seltzer tablets and exploring the relationship between amounts of reactants and products.
The purpose of this lab is to investigate the composition of a compound suspected to be Panacetin, a type of pain-killer. Panacetin is typically made up of sucrose, aspirin, and acetaminophen, but the third component in this experiment is unknown. The unknown component is suspected to be a chemical relative of acetaminophen, either acetanilide or phenacetin. Using techniques such as extraction, evaporation, and filtration, the three components will be isolated based on their solubilities and acid-base properties. Then, the percent composition of Panacetin can be deduced based on the masses of the three dried components. The
Unknown white compound (823U) was discovered in the lab. In order to dispose of it correctly, the substance and its physical and chemical properties had to be identified. The unknown white compound was one of a list of 15 compounds. 5g of the unknown compound were given in order to correctly identify and discover its physical and chemical properties. In order to do so, a solubility test, a flame test, and ion tests were conducted. From the results of these initial tests and the given list of compounds, the unknown white compound was thought to be composed of sodium and a halide (I-, Br-, or Cl-). Of the list, NaCl was the appropriate compound, however NaC2H3O3 was also tested out of skepticism. To verify the identity of the substance, the solubility and flame tests were performed again along with a pH test. The pH tests of NaCl and NaC2H3O2 did not match that of the unknown white compound. The list of compounds had been entirely ruled out. The identity of the unknown white compound was revealed to be calcium chloride. To synthesize at least a gram (calculated to produce 1.2g) of CaCl2, the following reaction was completed.
Pre-Lab: Analgesic drugs are known for reducing pain, while antiseptic drugs reduce symptoms such as fevers and swelling. However, some of these drugs can reduce both illnesses. To obtain a pure compound in these drugs, the scientist needs to separate the desired compound by taking advantage of the different physical and chemical properties. Such as; different boiling points, melting points and their solubility properties. To do this a chemist can also asses the differences between acidic and basic substances when they are added to water soluble mixtures. Within this current experiment I will asses the
19. A simplistic example of using some of this labs information in everyday life could be when I get acid reflux. Although it rarely happens to myself since I am fairly meticulous with my food choices and quantities, it can still creep up on me, and usually when this happens, like lots of people I go for the antacids. However, I think after this lab I may reconsidered the amount used, or throw the thought out completely since I now know that pH levels can affect how enzymes function. The stomach is a highly acidic pH environment and to try to offset the acid reflux the antacids are ingested since they are a base and will bring the pH levels up on the pH scale. The heightened level on the scale will help to lessen the stomach acid from wreaking havoc on your esophagus. Although this seems good, little do we realize that the antacids are also going to cause an enzyme in the stomach, pepsin, to not work correctly or at all since it needs an acidic environment to function properly. Pepsin is an enzyme responsible for protein breakdown into polypeptides, which will later be broken down into amino acids in the small intestine. I think since protein is the building block of all cells, I would think it would be best to keep this enzyme working efficiently. This is just one of the enzymes in the body being affected by altered pH levels, and other enzymes have their own requirements of pH levels to work properly as
Absorption – “How the drugs enter the circulation process through the body, and how they resist general breakdown by the stomach, liver, and the intestines”. Some of the factors that affect the absorption of drugs in the body is as follows, “acidity of the stomach, Physiochemical properties, Presence of food in the stomach or intestine, and Routes of administration”,
The hypothesis was formed under the thought that the fastest dissolving pill would be the most effective because the sooner the ingredients and materials were realized, the sooner they would be able to attack and neutralize the pain, therefore getting the job done quicker or more efficiently. The hypothesis was not supported because, overall, the first two pills to dissolve were both children’s pain killers and were “junior strength”. Therefore, these medicines could not have been the most effective because the strength is significantly weakened to accommodate to young kids, and would not be as effective as normal strength medicines. In order to accurately determine the time taken for the pills to dissolve inside the body, it is very important to create a solution similar to stomach acid. Stomach acid was simulated by heating vinegar, which has the same ph level of stomach acid and shares other similarities in makeup and properties. The vinegar was heated to 36.7 degrees Celsius and constantly stirred to represent the temperature and motion of stomach acid. Eight different pills were timed to see how fast they dissolved. Each type of pill was tested three times in order to find an average for each medicine. The pills tested were Advil, Children’s Advil Grape Flavored, Ibuprofen, Children's Ibuprofen Grape Flavored, Tylenol, Tylenol Liquid Gels, Aleve, and Aleve Liquid Gels. The children's strength pills were the first two medicines to dissolve. Aleve was the slowest to dissolve and took almost two hours to dissolve. The liquid gel capsules were the second and third slowest pills to dissolve. In order, from fastest to slowest to dissolve, the medicines were Children's Ibuprofen Grape Flavored, Children’s Advil
E. Generic drugs can have different manufacturers, which mean they can also have different inactive ingredients in it.
For this experiment, titrations on a weak acid, acetic acid, and a buffer were performed. Acetic acid was titrated with NaOH in order to observe the half-equivalence point as well as the equivalence point. Then, the buffer and the buffered acetic acid solution prepared faced additional titration with NaOH and HCl to evaluate the differing buffering effects following the addition of a strong acid and strong base. Finally, the buffer’s buffering capacity was calculated. If the experiment were to be repeated, it would be interesting to observe the buffering effects following a titration between a weak base and a buffer instead with greater concentrations. The change in the concentration following the preparation of buffer with a weak base and its conjugate acid would pose for an interesting experiment to observe an increase in the buffering capacity.