Determining the Ksp of Calcium Hydroxide by Titration of Saturated Ca(OH)2(aq) with HCl(aq)
Abstract: Titration is a technique that has been used in this experiment to identify the Ksp value of calcium hydroxide in order to determine the extent to which the compound is soluble in water. A known volume of 50 mL of hydrochloric acid, a concentration of 0.05 M hydrochloric acid, a volume of 50 mL calcium hydroxide base, an unknown concentration of base and an acid-base indicator (bromothymol blue) has been used in this experiment to determine the concentration of calcium hydroxide. From the results tabulated, a Ksp value of 1.26 x 10-7 has been retrieved indicating that
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All group members began by setting up the lab by obtaining all required materials and placing them on the lab bench. A buret was then rinsed twice with water and once with HCl(aq). It was then filled with 30 mL of the titrant, HCl(aq). The pipet was rinsed twice with water and once with Ca(OH)2(aq) . The pipet was filled with 10 mL of Ca(OH)2(aq) and then emptied into a flask. 20 mL of water and three drops of indicator was added to the flask containing Ca(OH)2(aq). The flask was then placed under the tip of the buret. The stopcock was rotated which allowed the addition of small amounts of titrant into the flask containing calcium hydroxide solution with bromothymol blue indicator which has a light blue appearance. In each trial, the base was titrated to the endpoint; the endpoint was where the solution in the flask changed colour from light blue to yellow. The buret readings were recorded before and after the titration was completed. Finally, the titration was repeated two more times, resulting in obtained data for all three trials. After the lab was performed, all equipments were washed and dried well by
The pre-test helped us decide the exact details of our experiment. We started off with testing 25cm³ of 3-molar hydrochloric acid to 2g of calcium carbonate medium size chips (we decided a medium size chips before we started our pre-test as we had a choice of 3, small, medium, large). We saw that this reacted too quickly as we used 10 second intervals and we couldn't get 6 results this is because our burette could only hold 100cm³ of water, which would make our results reliable. We then decreased the amount of Calcium Carbonate to 1g and kept the same 25cm³ of 3 molar hydrochloric acid and 10 second intervals. We could get the right amount of results of this, so we then tested the other extreme - the lowest molarity.
The hypothesis is; as we know the concentration of sodium carbonate (Na2CO3) we can obtain the concentration of hydrochloric acid using the titration of a standard solution.
In 2 and 7 I added 50 mL of .1 M NaCl. I added sodium acetate to the rest of the beakers: 1 gram to 3 and 8, 5 grams to 4 and 9, and 10 grams to 5 and 10. I then filled the beakers that contained the solid sodium acetate with 50 ml of .10 M acetic acid. Specifics can be found on page 84 of the lab manual. Though the lab manual instructed to use a pipet, we did not have an accurate 1 mL pipet or a graduated pipet, so we instead prepared two graduated burets with 1 M Sodium Hydroxide and 1 M hydrochloric acid. Using a standardized pH probe with a Lab Pro to measure changes in pH, we added 1 mL of HCl at a time and recorded the changes. The same was done for the NaOH.
The first experiment begun by filling a 600-ml beaker, almost to the top, with water. Next, a 10-ml graduated cylinder was filled to the top with water. Once water was added to the beaker and graduated cylinder, a thumb was placed over the top of the graduated cylinder. This would ensure that no water was let out and no bubbles were let into the graduated cylinder. Next, it was turned upside down and fully submerged into the beaker. Then, a U-shaped glass tube was attained. The short end of the glass tube was placed into the beaker with the tip inside of the graduated cylinder. Next, a 50-ml Erlenmeyer flask was received. After, 10-ml of substrate concentration and 10-ml of catalase/buffer solution were placed into the flask. A rubber stopper was then placed on the opening of the flask. After adding these, the flask was held at the neck and spun softly
To start off the experiment 25mL of water was placed into a labeled beaker and tested for the pH using pH test strips. Next the antacid tablet was placed in the solution and timed for how long it took to dissolve the tablet. Finally the temperature was measured. This same process was repeated for the acidic solution, and finally for the basic solution. After each experiment the pH, the reaction time, and the temperature of the beaker were recorded into a table. For this experiment the independent variable was the substance used (acid, neutral or base), and the dependent variable was the reaction time of each substance. The constant conditions of this experiment included the amount of substance being used, and the placing of one antacid tablet into each beaker. The experimental group was the acidic and basic solution, and the control group was the neutral
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
The mixture was then transferred to a clean centrifuge tube via pipet, carefully not wetting the upper walls of the tube. Zinc granules were then added and the tube was immediately plugged with cotton 1/3 of the way into the tube. The tube was then warmed in a hot water bath for about 5 minutes, the folded red litmus paper was inserted at the top of the tube with a wet crease. After a few minutes, nitrate is indicated on the wet crease of the litmus paper, turning it blue. For the Carbonate test, 25 mg of carbonate sample was added to a centrifuge tube and 3 drops of 6 M H2SO4 was added. A disposable pipet was used to transfer a drop of Ba(OH)2, that hung directly from the pipet over the carbonate solution, and the observations of the drop were recorded.
Please complete the entire experiment as instructed in the lab manual except for any modifications noted below. Fill out the
ii. The second part of the titration series involves titration of NaOH with Hydrochloric acid (HCL). Again, three reps of titration and a blank titration have to be completed. A volumetric pipet is used to measure 10.00mL of HCL into three labeled conical flasks. Then the flasks are filled with deionized water until about the 50mL mark. A buret is
The pipette was used to transfer 8 mL of the 0.5 molarity solution into the graduated cylinder. Distilled water was added to raise the bottom of the meniscus to the 20.0 mL line and the solution was transferred into the beaker after it was rinsed with the solution. The pipette was used to take a small quantity of the solution and rinse and then fill a test tube with the solution. The amount of 0.2 molarity solution needed to create 20.0 mL of 0.1 molarity solution was calculated as 10.0 mL. The pipette was used to transfer 10.0 mL of 0.2 molarity solution into the graduated cylinder and distilled water added until the bottom of the meniscus reached the 20.0 mL line. The solution was transferred to the rinsed beaker and then a portion placed into a test tube that had been rinsed with the solution. The amount of 0.1 molarity solution required to create 20.0 mL of 0.05 molarity solution was calculated to be 10.0 mL. The pipette was used to transfer 10.0 mL of 0.2 molarity solution into the graduated cylinder and distilled water added until the bottom of the meniscus reached the 20.0 mL line. The solution was then placed into a beaker that had been rinsed with the solution and then into a rinsed test
The purpose of this experiment was to determine the molar solubility, the solubility constant, and the effect of a common ion on the molar solubility of calcium hydroxide. To accomplish this the experiment was split into two parts; part A and Part B. in Part A of the experiment a standardized 0.05 M solution of HCl was titrated into a 25 mL solution of saturated Ca(OH)2 which contained 2 drops of orange methyl identifier. Once the titration began, the HCl was added until the methyl orange endpoint was reached, and as a result the volume of the HCl needed for the endpoint to be reached could be used in
Its concentration was found through a quantitative and qualitative titration testing. Because HCl is acidic, a 1.07M NaOH solution was used to titrate an aqueous solution of HCl (the unknown solution). The PASCO program gave the final results shown in Figure 1. A typical titration curve can be described as starting at the initial pH of the solution, then some acid/base is added, until a sharp curve either up or down takes the pH past a neutral of 7, and towards the pH level of whatever the added acid’s/base’s pH is (Clark6). The stronger the acid or base being titrated, the faster the change occurs, which means a sharper slope of the titration graph. Also, it is important to note the equivalence point on this titration graph. At the equivalence point “the correct amount of standard solution must be added to fully react with the unknown concentration” (Xavier3). In Figure 1, this equivalence point is shown by where the sharpest slope occurs in the curve, which is seen at about a pH of 5.0
In this experiment, the Ksp for calcium sulfate dihydrate, CaSO4·2H2O, by titrating 4 times a calcium sulfate dihydrate solution with diprotic EDTA, H2(EDTA)2-. For each trial we found the Ksp by means of molarities and activities. The results for the Ksp using only molarities was very different than the Ksp using activities. The average Ksp using molarity only was 2.26 x 10-4 and the average Ksp using activity turned out to be 2.31 x 10-5. The actual Ksp however, is 3.14 x 10-5. A percent error of 26.6 % was calculated.
The purpose of this lab was to use process titration to find concentration of an aqueous solution of Hcl(aq) , using KOH(aq) as the titrant.
A standard acid solution like HCl can be used as titrant for the analysis of both soda ash and a carbonate-bicarbonate mixture. In the analysis of soda ash, the volume needed to neutralize the soda ash is used to compute for its alkalinity, in this experiment we obtained a 17.6 % alkalinity with an error of 15.14% In the analysis of a carbonate-bicarbonate mixture two indicators (phenolphthalein and methyl orange) were used. The first endpoint determines the half-neutralization of the carbonate and the second determines that of the