Results and Discussion For the first part of the experiment (Part A), five different 100 mL volumetric flasks were each filled with 1,2,3,4 and 5 mL of iron (II) solution. Then 5 mL of YY ligand, were poured to each of the five flasks. Each flask had 5 mL of 2M sodium acetate and 4 mL of 3M NH2OH. Then the whole solution was diluted up to the 100 mL fill mark with distilled water. This was the solution that was used in order to obtain the absorption spectrum for each of the different iron (II) ligand examples different flasks.
Experimental First, we weighed 2 samples, each has 1 gram of NaHCO3-KCl mixture Second, we put the samples in 2 crucibles (A and B) and weighed them. (crucible + sample; WA1 and WB1) Third, we heated both samples on a hot plate for 30 minutes. Fourth, we weighed the samples again (crucible + sample; WA2 and WB2) Lastly, we determined NaHCU3 percentage in the mixture using the following method: WA1 – WA2 x 100% 0.309 WA1 – WA2 x 100% 0.309 * * Results * Theorectically: * Discussion When sodium hydrogen carbonate is heated, new products are formed; sodium carbonate, water vapor, and carbon dioxide gas. This reaction may be presented in a different form with a measure of molecules: @Na2CO3 + H2O + CO2 (solid) (solid) (gas) (gas). Once the reaction of sodium hydrogen carbonate takes place, carbon dioxide gas is released, as well as water vapor.
Data: Data Table 1 | | | Rubbing Alcohol Trial # | Boiling Point | Percent Error | 1 | 79.5 C | 3.52% | 2 | 84.0 C | 1.90% | 3 | 83.5 C | 1.30% | Data Table 2 | | | | Acetamide Trial # | Melting Point | Freezing Point | Percent Error (Melting Point) | 1 | 79.5 C | 57.5 C | 3.50% | 2 | 80.5 C | 59.5 C | 0.60% | 3 | 78.0 C | 61.0 C | 3.70% | Observations: It was observed that thermometer placement could affect the readings in the water bath. I ended up holding the test tube assembly to where the bottom of the test tube was not touching the bottom of the beaker to ensure better readings. Also, when substances recrystallize, I am not sure whether to take a reading when the substance has full crystallized or begun to so results could be fairly inaccurate. Questions: A. Why is it useful
Record the mass of thyme used. 2. Using a measuring cylinder, add 50cm3 of 1.0mol dm-3 sulphuric(VI) acid and boil gently for 5 minutes. 3. Allow the mixture to cool for a few minutes then filter it, using either gravity or vacuum filtration.
We selected a spirit burner and recorded the name of the fuel into our table; we also included the mass of the whole burner. We then clamped the steel can so that the spirit burner will fit under it. We light the wick of the spirit burner and placed it underneath the can. After we used the thermometer and to gently stir the water when the temperature increased by 20 we put the lid on the burner to put the flame out, we then recorded the new mass of the whole burner including the lid and fuel inside. We repeated thus experiment twice with each fuel, using clean water each time.
Gather all materials 2. Heat 200mL of water in the beaker for 90 seconds 3. Place the bulb of one thermometer just below the surface of the water 4. Record the initial temperature at the top 5. At the same time, place the second thermometer bulb just at about the bottom of the beaker 6.
10 mL of each solution [0.16M KI, 0.0055M (NH4)S2O8, 0.12M Na2S2O3, and water] were added to an Erlenmeyer flask along with about 0.2 g of starch and a drop of EDTA (to prevent coagulation) and mixed with a stir bar. The reaction was conducted twice for room temperature (24.5ºC), cold (1.5ºC), and warm (37.0ºC). Observations were made as the mixture changed from clear to a dark blue, almost black. The time for this color shift was recorded (in seconds). By varying the temperatures, variables A and Ea could be determined.
I inserted the digital thermometer into the test tube and took reading every 30 seconds until the readings remained constant. The readings for the distilled water did not change. I then placed the test tube in the beaker’s ice water bath and set the stopwatch at zero. I carefully stirred the water in the test tube with the thermometer and recorded the temperature of the water at 30-second intervals. Data Table 1: Pure Water Time in seconds | Distilled H2O Room Temp | Distilled H2O Ice bath | 0 | 2431o C | 24.3o C | 30 | | 4.8o C | 60 | | 0.7o C | 90 | | -0.4o C | 120 | | -0.8o C | 150 | | -.10o C | 180 | | -.10o C | Data Table 2: Salt Solution Time in seconds | Salt Water Room Temp | Saltwater Ice Bath | 0 | 20.8O C | 14.2o C | 30 | | 3.0o C | 60 | | 0.2o C | 90 |
Lab 2 Measurements: Accuracy and Precision A. Data Tables (36 points) Place your completed data tables into your report here: Data Table 1 Measurement | Data | Length of aluminum plastic packet | 4.50cm | Height of aluminum plastic packet | 7.50 cm | Temperature of faucet water | 26.0 degrees Celsius | Temperature of ice water | 10.0 degrees Celsius | Volume of water in 10-mL graduated cylinder | 10.0ml | Volume of water in 50-mL graduated cylinder | 9.0ml | Data Table 2 Measurement | Data | Inside diameter of 50-mL graduated cylinder | 2.50 cm | Height of 50-mL graduated cylinder | 10.0 cm | Water temperature | 25.0 degrees Celsius | Initial volume of water in 50-mL graduated cylinder | 10.0 mL | Mass of water in the 50-mL graduated cylinder (remember, 1 g of water weights 1 mL since its density is 1 g/mL) | 10.0gm | Volume of water and aluminum shot in 50-mL graduated cylinder | 18.0ml | Mass of aluminum shot (given on outside of packet) | 20.0gm | B. Follow-Up Questions (Show all calculations) Part I (Each question is worth 10 points.) 1. Convert the length and height measurements for the packet that contains the aluminum shot from units of cm to units of mm using the unit-factor method.
Using another 125-mL flask, 60-mL of 0.3622 M potassium hydroxide in ethanol was deposited. Both flasks were clamped in a temperature-controlled bath regulated at 50.0˚C. The solutions were then set in the temperature bath for ten minutes to equilibrate. An empty 250-mL Erlenmeyer flask was also clamped in the same water bath. In another flask 50-mL of ice water was deposited with three-drop phenolphthalein.