Add 1 mL of deionized water to the small test tube containing the precipitate and mix it and centrifuge it for 60 seconds. Then, add the supernatant into the boiling test tube and repeat this step one more time with another 1 mL of deionized water. Acquire a pair of metal test tube holders and heat the boiling test tube to evaporate the water for 15 minutes. Let is cool after and weigh it. Then, calculate a percent yield of zinc iodide and write a balanced chemical equation and determine the limiting
At first we dried the crucible in the flame three times and let it come to a constant mass by measuring the weight each time. To determine percentage of water in Epsom salt, we measured about 2g of the salt into three different, dried crucibles. The crucibles were first heated gently, then intensely to drive off all the water. The final data was reported as percent hydrate with 95% confidence level. RESULTS & DISCUSSION Weights of the crucible.
Begin by adding 1 mL of rubbing alcohol to test tube and attach a thermometer to it. b. Place assembly in water bath and begin to heat beaker c. As isopropyl alcohol begins to boil, bubbles begin flowing from the capillary tube d. While temperature is decreasing, record the temp. when the last air bubble comes out of the capillary tube. e. Let assembly cool down and repeat process two more times.
Then 5mL of HCl was added to copper to completely remove all traces of zinc. Once the bubbling had stopped, the rest of the liquid was decanted away from the copper. Then the copper recovery set up was put together using tubing, Buchner funnel, filter paper and suction flask. Then the filter paper was weighed before placing it in the funnel and wetted down. The aspirator was turned to medium high, and then the copper was poured onto wetted filter paper.
Using a test tube holder, heat the R tube over the Bunsen burner, moving the tube in a circular motion until all the water has evaporated. The P tube will be carefully heated next, for about 10 minutes, until all the water has evaporated, and there is a white substance in the tube. After the water has evaporated, continue heating the tube over the burner for a minute longer, being careful to watch out for purple gas and yellow spots. The P tube
Next was the ammonia test 10 drops of each metal solution were added to new centrifuge tubes and 15 M NH4OH was added until the solution changed color or a precipitate was formed. 10 additional drops of 15 M NH4OH were added and changes were recorded. For the confirmation flame test 20 drops of the metal solutions were added to centrifuge tubes. A Bunsen burner was set up using a striker to lite the flame, and a Nichrome loop was dipped in 10 mL of HCL and placed in the flame till no color was observed. Then the Nichrome loop was dipped in each tube of metal solution, (dipping the loop into HCL and in the flame after each solution) and placed in the flame and color was observed for each metal solution.
Experiment 2 Time | Observations | 5 minutes | Bubbled like sugar | Once salt water was added | Turned soapy white and thick | Equation: METHOD 1) Put 2 cm3 of castor oil into a 250 cm3 beaker and add 10 cm3 of 5mol.dm-3 sodium hydroxide from a measuring cylinder. (Take care when measuring this out and adding it to the beaker to avoid any drips and spills.) 2) Heat the mixture gently over a tripod and gauze, STIRRING CONSTANTLY with a glass rod (otherwise the mixture erupts). Allow to simmer (boil gently) for 5 minutes. Steady the beaker using
The experimenter used 3 identical plastic cups and filled one with room temperature tap water, one with warm tap water and one with boiling tap water. Each cup was placed into the freezer and was checked every 15 minutes for signs of freezing. The experimenter found that the room temperature water showed the first signs of freezing and in the final outcome froze solid before the water in the other cups. His findings showed that water containing impurities, such as tap water, will freeze faster based on a lower starting temperature. The second case study was covered in an article by Science News.
In this lab we synthesized and analyzed potassium aluminum sulfate (KAl(SO4)12H2O) using a multiple different tests. These test included flame test, melting point, potassium test, sulfate test, and aluminum test. We also determined the number of waters of hydration in Alum. Experimentally and empirically potassium aluminum sulfate is a dodecahydrate (4). The purpose of the laboratory is to determine the number of waters of hydration in aluminum potassium sulfate as well as the purity of the Alum we produce.
The reaction was monitored and removed from the heat once the effervescence ceased, and then was allowed to cool. Concentrated hydrochloric acid was added while heating and stirring the reaction for 15 minutes. The product was then allowed to cool and was vacuum filtered to a maroon color, while being washed with water, 6M hydrochloric acid, ethanol, and acetone. Then allow the product to dry for five minutes on the funnel. The resulting product was [Co(NH3)5Cl]Cl2 and yield was 4.453g (.017 mol, 84.8%) Distilled water (25mL) was added to concentrated ammonia (5mL) in a 125mL Erlenmeyer flask.