Study of Solubility Equilibrium of Khc4H4O6

Temperature is known as one of the factors that affect the solubility of a gas in its solvent. Because the enthalpy of solution for gases dissolved in waters is usually

3.0g of salicylic acid was weighed then 3.0mL of acetic anhydride and 6 drops of 85% H3PO4 were added to it. The mixture was warmed over a water bath for 5 minutes while stirring. After warming, 20 drops of distilled water was slowly added. 15mL of water was added then the solution was heated until it became clear. It was allowed to cool and was placed in an ice bath until the solution becomes cloudy. Using pre-weighed filter paper, the mixture was filtered and was allowed to dry in the filter paper.

21) After all of the solid dissolves, move the flask from the hot plate and allow it cool to room temperature. After a while, crystals should appear in the flask.

1.5mL of phosphoric acid including 3-4 boiling chips were also added to the 25mL flask. The short path distillation apparatus was set up as shown in Figure 1. A heating mantle was used to heat up the 25mL flask. The solution was distilled to the receiving flask until a small amount of liquid remained in the initial RBF flask. At this point the presence of thick grey smoke pulling over into the entire apparatus was observed. The apparatus was then left to cool down. Through the use of pasture pipette, the aqueous layer from the distilled solution was drawn out. Sodium carbonate was then added to the remaining organic solution in order to check the pH and to verify the basicity of the solution. The aqueous layer was again drawn out from the solution. Next, 0.5g of sodium sulfate was added to the remaining organic layer and was swirled until the liquid appeared to be dry and clear. The alkenes were transferred into a clean 10mL flaks using another clean pasture pipe. The apparatus from the first distillation was rinsed off with

The purpose of this experiment was to determine the pKa, Ka, and molar mass of an unknown acid (#14). The pKa was found to be 3.88, the Ka was found to be 1.318 x 10 -4, and the molar mass was found to be 171.9 g/mol.

Procedure: Filled each test tube with substances provided and subjected them to various conditions. These conditions included, heat, cold water, hot water, acid and basic additions and tested on litmus paper. The reactions were observed and documented at each step.

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.

Methods: First, a burette, ring stand, clamp, and an empty flask were obtained. The burette, with the valve closed, was attached to the ring stand with a clamp, and the empty flask was placed below the burette. Next, 50mL of the NaOH solution were poured into the burette, and a small bit was drained into the empty flask to ensure that the tip of the burette was also full of NaOH solution. The volume of the NaOH in the burette was recorded. Next, approximately 0.6 grams of KHP were massed poured into an empty 125mL flask. Two drops of an indicator solution were added to the KHP

In this experiment, hydrochloric acids at different temperatures will be used to observe the effect of temperature in dissolving Alka Seltzer tablets. Four different temperatures as 25 degrees Celsius, 45 degrees Celsius, 65 degrees Celsius, and 85 degrees Celsius will be arranged before the experiment by using a heating pad. 25 degrees Celsius indicates the average room temperature and equal increases will be chosen to observe different responses of Alka seltzer to different temperatures.

It is necessary to determine the mass of the anhydrous compound immediately because they are highly sensitive to humidity in the environment and will absorb any oxygen present, which, in turn, will elevate the compound’s mass and alternate the experiment’s results.

Approximately 3.4 grams of K2HPO4 was weighed on a triple beam balance and dissolved in 100.00 mL of DI water by diluting to the mark in a volumetric flask. Similarly, 2.4 grams of NaHPO4 was weighed on triple beam balance and dissolved in 100.00 mL of DI water by diluting to the mark in a volumetric flask.

A hot plate was preheated to 100°C. A dry 5-mL long-neck round-bottom flask was clamped over an aluminum block placed on the hot plate. Ferrocene (0.09 g), acetic anhydride (0.35 mL), and 85% phosphoric acid was added to the flask in that order of addition. A magnetic stir bar was added to the flask. Solution was stirred and heated for 10 minutes. Flask was removed and allowed to cool to ambient temperature. DI water (0.5 mL) was added and the solution was cooled to 0°C by ice bath. The solution was neutralized with 3M sodium hydroxide dropwise while stirring and cooling. PH was monitor by pH indictor paper. Solid product was isolated by vacuum

After the mixture finished refluxing, the flask was then cooled on ice. A sulfuric acid solution was then prepared by pouring 4.5 mL of concentrated H2SO4 over 50 grams of ice and then diluted to 75 mL by adding enough tap water to reach 75 mL. The sulfuric acid solution was then cooled on ice.

Once cooled, the mixture was then transferred to a separatory funnel using the funnel while avoiding adding the boiling chip. 10 ml of water was then added to the mixture. The mixture was gently shaken and the phases were allowed to separate. The funnel was then unstopped and the lower aqueous phase was drained into a beaker. 5 ml of 5% aqueous NaHCO3 was added and then shaken gently. A great deal of caution was taken into consideration because of the production of carbon dioxide gas which caused pressure to develop inside the funnel. The pressure needed to be released so the funnel was vented frequently. The phases were allowed to separate and the lower aqueous phases was drained into the beaker. After draining, 5 ml of saturated NaCl was added to the funnel and then shaken gently. Once again, the phases were allowed to separate and the lower aqueous phase was drained into a beaker. An ester product was produced and was transferred into a 25 ml Erlenmeyer flask. This organic product was then dried over anhydrous Na2SO4 to trap small amounts of water in its crystal lattices thus removing it from the product. Finally the ester was decanted, so that the drying agent was excluded from the final product.

An ice bath was prepared in a large beaker and a small cotton ball was obtained. 0.5 g of acetanilide, 0.9 g of NaBr, 3mL of ethanol and 2.5 mL acetic acid was measured and gathered into 50mL beakers. In a fume hood, the measured amounts of acetanilide, NaBr, ethanol and acetic acid were mixed in a 25mL Erlenmeyer flask with a stir bar. The flask was plugged with the cotton ball and placed in an ice bath on top of a stir plate. The stir feature was turned on a medium speed. 7mL of bleach was obtained and was slowly added to the stirring flask in the ice bath. Once all the bleach was added, stirring continued for another 2 minutes and then the flask was removed from the ice bath and left to warm up to room temperature. 0.8mL of saturated sodium thiosulfate solution and 0.5mL of NaOH solution were collected in small beakers. The two solutions were added to the flask at room temperature. The flask was gently stirred. Vacuum filtration was used to remove the crude product. The product was weighed and a melting point was taken. The crude product was placed into a clean 25mL Erlenmeyer flask. A large beaker with 50/50 ethanol/water