Add 1 drop of Na2 EDTA to C2 and stir, add more drops until color changes, record observations 9. Suck up the mixture in C3 into a pipet 10. Place the C3 pipet in hot bath. Attach pipet to side of beaker with clothespin to prevent it from floating, 11. Repeat step 10 but with C4 and place in ice bath.
Obtain beaker filled with 250 mL of HCl and 5 pennies. 2. Get a pipette and remove 10 mL of that solution (HCl + Zn) and place it in a 100 mL beaker. 3. Add color indicator 4.
10 drops of each cation that are left are added to clean centrifuge tubes. 15M NH4OH was added dropwise until a color change or a precipitate was formed with no more than 20 drops added. A cation should be eliminated. If the solution formed a precipitate before, then 10 more drops of the 15M NH4OH was added to the solution. The last two cations should be separated with the observations of the additional NH4OH added.
II. Procedure Use a 10-mL graduated cylinder to put 6mL of 6 M sodium hydroxide solution (NaOH) into a clean 500mL storage bottle. Use a 100mL graduated cylinder to add 345mL of distilled water to the plastic bottle. Place a lid on the bottle and mix by shaking repeatedly. Sit the bottle off to the side for later use.
Chlorine gas can be produced in the laboratory by adding concentrated hydrochloric acid to manganese(IV) oxide in the following reaction: MnO2(s) + 4HCl(aq) ( MnCl2(aq) + 2H2O(l) + Cl2(g) a. Calculate the mass of MnO2 needed to produce 25.0 g Of Cl2 ans: 30.7 g MnO2 b. What mass of MnCl2 is produced when 0.091 g of C12 is generated? ans: 0.16 g MnCl2 1. How many moles of ammonium sulfate can be made from the reaction of 30.0 mol of NH3 with H2SO4 according to the following equation: ans.
Now to begin, pour 50 mL of the sodium phosphate buffer solution with a pH of 6.84 into the 150 mL beaker. From here on out, the sodium phosphate buffer solution will be referred to as simply the buffer solution. Next, locate the indicator called bromothymol blue (0.04%) and add 20 drops to your 150 mL beaker. The solution should then appear green. Next, obtain a 5 mL serological pipet and thoroughly rinse it with the buffer solution, then discard the buffer solution into the 250 mL beaker.
| Experiment #3Weight of Zinc: 2.0 gramsWeight of Iodine: 1.1 gramsExperiment #6Weight of Zinc: 2.02 gramsWeight of Iodine: 2.5 grams | 3. Then add 5 mL of acetic acid (acidified water) into the “R” boiling tube, and then after you pour it swirl vigorously. Continue swirling until the tube turns back into room temperature. Then you have to decant the solution in boiling tube “R” into boiling tube “P” without any granular zinc leaving boiling tube “R”. Then wash the zinc in the boiling tube “R” by adding 5 mL of acidified water, swirling and then decanting the solution into the “p” boiling tube.
| Experiment #3Weight of Zinc: 2.0 gramsWeight of Iodine: 1.1 gramsExperiment #6Weight of Zinc: 2.02 gramsWeight of Iodine: 2.5 grams | 3. Then add 5 mL of acetic acid (acidified water) into the “R” boiling tube, and then after you pour it swirl vigorously. Continue swirling until the tube turns back into room temperature. Then you have to decant the solution in boiling tube “R” into boiling tube “P” without any granular zinc leaving boiling tube “R”. Then wash the zinc in the boiling tube “R” by adding 5 mL of acidified water, swirling and then decanting the solution into the “p” boiling tube.
10 drops of NaOH were added to each precipitate to test for amphoteric species. The contents were rinsed with distilled water and the tubes were cleaned with 6 M HCl. For the ammonia elimination test, 10 drops of each cation solution were placed in their tubes and 15 M NH4OH were added dropwise till a precipitate or color complex was observed or till 20 drops were reached. 10 drops of 15 M NH4OH were added and additional changes were recorded. The contents were disposed of and rinsed with distilled water.
Comparing and Contrasting: Compare the ratio of moles of iron to moles of copper from the balanced chemical equation to the mole ratio calculated using your data. 8. Evaluating Results: Use the balanced chemical equation to calculate the mass of copper that should have been produced from the sample of iron you used. Use this number and the mass of copper you actually obtained to calculate the percent yield. 9.