Acid Concentration

Two acid-base reactions were used to result in the percent by mass of NaHCO3 in Alka-Seltzer tablets:

This experiment involved three steps: synthesis of aspirin, isolation and purification, and the estimation of purity of the final product. The synthesis involved the reaction of salicylic acid and acetic anhydride in the presence of a catalyst, phosphoric acid, H3PO4. When the aspirin was prepared, it was isolated and filtered. The percentage yield of the synthesis was calculated to be 78.42%. The experimental melting point range of aspirin was determined to be 122 -132°C. Due to its wide range, and lower value than that of the theoretical melting point of 136°C, it was

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

HCl will not react with aspirin to form a water soluble salt, so the aspirin will stay in the organic layer and will not be obtained. So that leaves the reported weight of the unknown to be too high.

The problem that was trying to be solved in this study deals with analyzing unknown solutions. In this particular case, a chemical company has several unknown solutions and to correctly dispose of them they need to know their properties. To figure out the properties several qualitative tests were performed throughout the study (Cooper 2012).

Chemistry 102 is the study of kinetics – equilibrium constant. When it comes to the study of acid-base, equilibrium constant plays an important role that tells how much of the H+ ion will be released into the solution. In this lab, the method of titrimetry was performed to determine the equivalent mass and dissociation constant of an unknown weak monoprotic acid. For a monoprotic acid, it is known that pH = pKa + log (Base/Acid). When a solution has the same amount of conjugate base and bronsted lowry acid, log (Base/Acid) = 0 and pH = pKa. By recording the pH value throughout the titration process and determining the pH at half- equivalence point, the value of Ka can be easily calculated. In this experiment, the standardized NaOH solution has a concentration of 0.09834 M. The satisfactory sample size of known B was 0.2117 g. The average equivalent mass of the unknown sample was found to be 85.01 g, pKa was found to be 4.69, which was also its pH at half-equivalence point and Ka was found to be 2.0439×〖10〗^(-5). The error was 1.255% for equivalent mass and 0.11% for Ka. In other word, the experiment was very precise and accurate; the identity of the unknown sample was determined to be trans-crotonic by the method of titrimetry.

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

The purpose of this virtual lab is to observe the acid-base balance in the urinary system by how PCO2 and blood pH affect the H+ and HCO3- in the urine. The renal compensation is a mechanism that shows the kidneys manage to change pH in correct way if the respiratory system is not healthy. The kidneys are two organs that help remove wastes and extra fluids out of the body. The acid-base balance is when the blood need to keep the balance of

Intermediate stability tests will be performed on samples from these batches of capsules at 30°C ± 2°C/65% RH ± 5% RH over a period of 6 months. Accelerated stability tests will be performed on samples from these batches of capsules at 40°C ± 2°C/75% RH ± 5% RH over a period of 6 months. These will also be tested according to the following matrix design.

The acetaminophen tablets from the Well at Walgreens brand showed a degradation of percent label claim of acetaminophen characterized by a R¬2 value of 0.4728 on a downward sloping treadline. The control percent label was found to be 105.3%. The percentages for weeks 2, 4, 6, and 8 were as follows: 111.9%, 88.7%, 100.9%, and 88.2%. Therefore, the total degradation found in the group results is a loss of 17.3% label claim. No outliers were determined at this time. The reason for this large amount would have to be the experimental conditions (70 C°, 75% RH), as these conditions are well outside of the recommended conditions shown on the label (15 – 30 C°). These extreme conditions led to a decrease in the amount of active acetaminophen present

By using acid-base titration, we determined the suitability of phenolphthalein and methyl red as acid base indicators. We found that the equivalence point of the titration of hydrochloric acid with sodium hydroxide was not within the ph range of phenolphthalein's color range. The titration of acetic acid with sodium hydroxide resulted in an equivalence point out of the range of methyl red. And the titration of ammonia with hydrochloric acid had an equivalence point that was also out of the range of phenolphthalein.. The methyl red indicator and the phenolphthalein indicator were unsuitable because their pH ranges for their color changes did not cover the equivalence points of the trials in which they were used. However, the

Acetaminophen, thiourea, and the three respective ratios were prepared and characterized by ATR FT-IR, PXRD, and DSC analysis.

Each antacid solution, consisting with one tablet and 20 mL of HCl, was titrated in the total of two trials with the exception Medi-First which had three trials. Table 2 shows the amount of HCl neutralized in moles and the volume of NaOH dispensed in

An acid-base titration is the determination of the concentration of an acid or base by exactly neutralizing the acid/base with an acid or base of known concentration. This allows for quantitative analysis of the concentration of an unknown acid

Ang gamot na ito ay tunay na natuklasan sa kalagitnaan ng 19 siglo. Ang pruso kemiko Adulf Von Bayer, ay maikredito sa imbensyong pagbibigay ng pangalan sa berbituric acid sa 1863-1864. Ginawa ang acid mula sa isang tambalan ng malonic acid at urea, 1903 na sa mga mag-aaral ng Bayers, kasama ang isa pang Aleman pharmacist, ginawa ang isang bagong tambalan ng barbituric acid at isang diethyl nanggaling. Ang bagong kemikal na ibinigay kalakalang pangalan Veromal, na isang mahusay na gamot na pampaginhawa at Sleeping Aid. Isa pang pananaliksik ay dumating pataas gamit ang bagong barbiturates sa 1920’s at 1930’s.