1. Firstly, a burette was taken and rinsed with distilled water. Then it was rinsed using the provided NaOH solution. 2. The burette was filled with the NaOH solution. 3. Next, 0.6gram of oxalic acid dehydrate was taken and weight. It is then added to a 125ml Erlenmeyer flask. 4. About 25ml of distilled water was added. Then 2-3 drops of phenolphthalein indicator solution were put in. It was swirl to dissolved the solid. 5. The initial volume of NaOH solution in the burette was noted. 6. The oxalic acid dehydrate solution was titrated using NaOH solution until light pink color can be seen. (does not disappear when the solution was mixed). 7. The final volume of NaOH solution in the burette was noted. 8. The molarity of NaOH solution was calculated. 9. …show more content…
The above process was repeated three times. 10. The average results were recorded and calculated. B) Analysis of ibuprofen 1. 50 ml of glycerol and 50 ml of distilled water was added inside an Erlenmeyer flask. It was heated to 60 Celsius. NaOH solution was added gradually drop by drop until rose color was observed. 2. One tablet (ibuprofen) was crushed using mortar and pestle. It is then put into the flask. The content was stirred using a glass stirring rod. 3. 1-2 droplets of phenolphthalein indicator were put in. It was titrated until red color can be observed. 4. The steps above were repeated twice and the result was
neutralize 35ml of our base. Once we weighed out the KHP we then dissolved it
· Rinse out mixture in flask and leave water running to get rid of the
Above in table 4.1 the results are shown. Test tube 2 was the only tube that had a change in color. The reason that test tube 2 was the only one that changed in color was because a reaction that was produced by catechol oxidase. Tube 2 was the only tube that had potato extract and catechol this is why the reaction occurred. The potato extract and catechol was not present at the same time in the other tubes and that is the reason they had no change.
The Solution inside the burette was unveiled slowly and mixed together with the Acid “A”. The flask was swirled continuously to ensure the Sodium Hydroxide is thoroughly mixed.
In acid-base titration solution without a known molarity is placed in an Erlenmeyer after it’s volume is measured. An indicator is added to the solution most of the time it is phenolphthalein. The solution with a known concentration is placed in burette with a tap in the end. By opening the tap slightly solution in the burette is poured in to the solution in Erlenmeyer drop by drop. After a while the solution in Erlenmeyer forms a color change. This is the turning point for the solution. At the turning point by the volume consumed in burette the molarity of the other solution can be
of holding 250mL and mix contents. Place an O2 sensor in the mouth of the Nalgene bottle thus
Obtain and zero two burets, one containing .0500M oxalic acid and the other containing the permanganate solution. Next, add 25.00mL of the oxalic acid into a 250mL Erlenmeyer flask (using the bottom of the meniscus for measurements). Then proceed to measure and add 15mL of 3M sulfuric acid to the titration flask with a graduated cylinder. Heat the titration flask to a temperature of 80C. Titrate the contents of the flask with the permanganate solution. Swirl the contents of the flask after adding the permanganate and if the solution drops below 80C heat the flask back up to 80C. Use the top of the permanganate solution to take measurements rather than the bottom of the meniscus. Add just enough permanganate to turn the contents of the flask a light pink color. At this point record the volume of the permanganate solution used. Rinse the titration flask with distilled water and run the experiment one more time.
However, there is no color change at end point of these reactions, so an indicator had to be added into the solutions to indicate the end point. An indicator is a chemical which is used to indicate the presence of the another substance in the solution; it changes colors when the ions H+ are added or removed by dissociation reaction. In this experiment, phenolphthalein was used as an indicator to indicate the presence of base in a solution by changing the color of the solution from colorless into pink. When the concentration of H+ is low, the solution becomes pink, and when the concentration of ions H+ is high, it becomes clear. The equivalent point is determined when there is a color change from colorless into light pink, and it is also an approximation of the end point. The concentrations were calculated by the equation M1V1 = M2V2, which means that the moles number of the base must equal to the moles number of an acid. The mole ratio in these reactions are 1:1 that means the moles’ number of the first reactant is equal to the moles’ number of the second one at the end
Place 3ml of solution 1 intro a test tube. Heat it to boiling in a water bath. Allow it to cool and then add 3ml of H2O2 to the test tube. Note the result and record it.
The experiment used Potassium permanganate (KMnO4), a purple substance; Potassium dichromate (K2Cr2O7), a yellow substance; and Methylene Blue, a blue substance. These substances have molecular weights, 158 g/mole, 294 g/mole and 374 g/mole. A petri dish containing agar-water gel with three wells was obtained as shown in Figure 1. Each well was labelled as potassium permanganate, potassium dichromate and methylene blue. One drop of every prepared substance was carefully placed into its respective wells in the agar-water gel using a dropper. The petri dish was immediately covered to avoid the possible effects of other foreign factors. The substances, each having specific colors, spread in the agar-water gel as shown in
in 5cm³ of water and add 4cm³ of ethanol. We had tom pour this mixture
...d solution of ascorbic acid. As a result, the first three titres were used even though the first one was a rough try.
An acid-base indicator is a substance that undergoes a distinct colour change at or near the equivalence point. The point in the titration at which the colour change occurs is called as end point. Obviously, the titration will be accurate only if the end point and the equivalence point coincide fairly closely. For this reason, an acid-base indicator used in this acid-base titration must be selected carefully in order to obtain an accurate result. Thus, the acid-base indicator used in this experiment is the phenolphthalein. Besides, phenolphthalein is also a suitable indicator for titration between a strong base and a weak acid. Phenolphthalein is colourless in an acid solution but pink in base solution. Phenolphthalein was added into both original oxalic acid (C2H2O4) and acetic acid (CH3COO) solution before the acid-base titration was carried out. Phenolphthalein is a weak acid and is represent as Hln in the following chemical
First we pour 10mL of infiltration solution and 30mL of sodium bicarbonate in a small beaker.
A. a 0.112 per cent w/v solu-tion of orthophosphoric acid adjusted to pH 7.0 using a 4.2 per cent solution of sodium hydroxide,