b) Add 3 drops of silver nitrate solution c) Note any color changes occurring d) Write a net ionic equation for any reactions that produces a precipitate e) Add a few drops of nitric acid to the test tube to acidify the solution. f) Mix well and note what happens to the precipitate. 4) In the third test tube: a) First add 1ml of bleach to a graduated cylinder adding 5mL of tap water and 6 drops HCL; Label an empty pipet and collect the solution into it. b) Br and I add 10 drops of the test solution to add 2 to 3 drops of the organic reagent and several drops of the chlorine water. Shaking the solution well, allow the lower layer to settle Note the color of the layer.
11.Repeat procedure again. Part Two 12.Use the thiosulfate to refill the 50 mL buret. 13.In a Erlenmeyer flask, add 1 mL of bleach. 14.Add this Erlenmeyer flask to 25 mL of distilled water. 15.Dissolve 2g of KI in the flask.
.40g of NaH_2PO_4, and .40g of Na_2HPO_4 was measured into a 150 mL beaker. 50mL of distilled water was then measured in to a graduated cylinder and added to the 150ml solution of NaH_2PO_4 and Na_2HPO_4. 20 drops of the .04% Bromothymol blue solution was then also added to the buffer solution. After adding the 20 drops the tint of the liquid changed to a light green. The Vernier pH probe was calibrated and used to determine the pH of the phosphate buffer solution which was 6.81.
At 50C our results indicated a solubility of 89 g/100mL of H2O which was close to the known solubility of 80 g/100mL. Introduction: When a salt, such as potassium nitrate or sodium chloride, is placed in water a dissolving reaction will occur. At first, the positive and negative ions of the salt compound are only attracted to each other. In order for the salt to dissolve, these bonds must be broken so that the ions disassociate from each other. In the water molecules, hydrogen is slightly positive and oxygen slightly negative so they are attracted to ions of the opposite charge, known as dipole attraction.
25 ml of diluted unknown acid solution to 100ml beaker by using 25 volumetric pipet. 10ml of deionized water and 3 drops of phenlpthalin indicator the beaker labeled as 3. Potentiometric titration acid solutions 125 ml of NaOH was obtaining in a beaker and 50 ml of NaOH transfer to buret the tip and the meniscus is at below 0 ml. one magnetic stirring bar placed in a beaker contain one of the known solution on a stir. The pH recorded by using pH electrode before adding NaOH.
Using a pipet, transfer the methylene chloride solution to a 50 mL Erlenmeyer flask. To this solution, add a scoop of anhydrous sodium sulfate (Na2SO4), in order to remove the last traces of water. 10. While the solution is drying, weigh (tare) a 50 mL beaker to the nearest 0.001 g on a balance. Record this tare weight in Table 1 on the DATA SHEET.
Materials and Methods: To begin the experiment, a sample of approximately 1 gram (1.01 g) of aluminum can pieces was obtained. Once the sample was placed in the 250 mL beaker, 50 mL of a 1.4 M potassium hydroxide solution were added to the beaker. The solution was placed on a hot plate and stirred in order to accelerate the reaction. During the reaction, observations were made and written down in our laboratory notebooks. Upon the reaction’s completion, the solution was filtered using an aspirator (filter and vacuum) so that all of the remaining undissolved aluminum waste was removed from the solution.
Then prepare the unknown sample by pipetting 1 ml of the unknown solution into the cuvette and mix with 1 ml of dilute ferric nitrate. Then after that you calculate the concentration for each of the solutions. Cuvette # | 25 mg/dl Standard | H2O ml | Dilute Iron III Nitrate (ml) | .039 M HNO3 (ml) | Concentration | 1 | 0 | 1 | 0 | 1 | 0 | 2 | 0.1 | 0.9 | 1 | 0 | 0.09 | 3 | 0.3 | 0.7 | 1 | 0 | 0.287 | 4 | 0.5 | 0.5 | 1 | 0 | 0.407 | 5 | 0.7 | 0.3 | 1 | 0 | 0.706 | 6 | 1 | 0 | 1 | 0 | 1.316 | When then use the calibration curve to determine the concentration of the unknown and we get .747. IV. As you can see from our data as the amount of H2O decreases and the 25mg/dl standard increases as does our concentration for the salicylic acids.
The buret was monitored to ensure that the solution extended to the tip of the buret and that no air bubbles were present because both would cause an inaccurate titration. The initial volume of the buret was then recorded to the nearest .02 milliliter. A 25 mL pipette was then used to measure exactly 25 mL of the KIO3 solution into a clean 250 mL beaker. 40-50 mL of deionized water was then added to the solution as well as about.5 grams of solid KI. The solution was stirred until all of the solid KI had dissolved.
Step 1using a clean 10-ml pipet, transfer precisely 4.00, 3.50, 3.00, 2.50, and 2.00 ml of tap water to five separate test tubes. Step2: after rinsing the pipet with a small quantity of antifreeze, transfer precisely 1.00, 1.50, 2.00, 2.50, and 3.00 ml of antifreeze to the 70-mm test tubes to give a total added volume of 5.00 ml in each tube. Step3: stir up each tube to ensure methodical mixing of the liquids. The resultant mixtures are normally 20, 30, 40, 50, and 60% antifreeze by volume, respectively. Step4: weigh a precisely measured volume (ca.