Make sure to keep time, read the spectrometer, and record the data. Note time to the nearest second and mix the contents of tubes 2 and 3 by pouring them back and forth twice. Mixing should be completed within ten seconds. 5) Add the reaction mixture to a cuvette by pouring or using eye dropper, wipe the outside, and place the cuvette in the spectrometer. Read the absorbance at 20 second intervals from the start of the mixing.
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
*Then add two drops of phenolphthalein indicator to the beaker by right clicking, choosing indications, and adding 2 drops of phenolphthalein. * Next is obtaining a 50 mL buret and to fill it 50 mL of 0.1 M NaOH solution. Do this by right-clicking on the working area, select a 50 mL buret, right-click on the buret, and choose Chemicals. * The last step is to Titrat Unknown Acid A with NaOH until the end point. Once again, right click on the working area, right click the beaker,
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.
For every 20 drops of solution you will add 0.1g of zinc to the new test tube. Repeat steps 3 and four until the solution is clear. If there ever exists too little of the solution to get enough drops, add up to 1mL of distilled water to the solution. 4. Once the solution is clear, retrieve at least ten drops of the solution and place them in a new test tube.
Heats of Solution and Reaction Name: Cindy Hernandez Purpose: The purpose of this experiment is to decided if the chemical reactions are exothermic and endothermic. By finding the differences between each temperature. Overview: For this lab, we had three different chemicals involved NH4Cl, H2SO4, and NaOH. What we did with these chemicals was that we added water, except NaOH we added HCl, was that we combined both mixtures to determine if there was a temperature change. The reason why we're determining if their was a chemical reaction is to identify if it is exothermic or endothermic.
Why is this necessary? Obtain an appropriate amount of 5.00 M NaCl and fill your 25 mL buret. Pipet a 20.00 mL aliquot of 0.100 M acetic acid solution into a 100 mL beaker, add a magnetic stirring bar, and then set up the titration apparatus as indicated in Figure 1. Record the initial pH and then begin titrating. You will titrate in 0.25 mL intervals for the first 2 ml and then in 1 mL intervals until a total of 6 mL of 5.00 M NaCl has been delivered.
5mL of acidified water will be measured, using a graduated cylinder, and will be transferred to the R tube, and will be immediately vigrously mixed with the reactants. Once the solution turns to an orange or red-brown color, a pipet will be used to quickly remove 30 drops of the solution, then transferred to the C tube, and the mixing will resume until the solution is close to room temperature. The solution will be filtered into the P tube, and the solution that is left in the R tube should be washed three times with 1mL of acidified water each time. The water should then be poured into the P tube, leaving the solid in the R tube. 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.
Then measure the final mass of the fuel using a mass scale. Record all the results. Repeat all the steps again, but change fuel (Cheetos, half a cashew nut, wax candle and ethanol) every three trials. Data Collection and Processing: Fuel | Trials | Mass H2O (ml) ±1 | Change in Water Temperature (°C) | Mass Loss of Fuel (g) ±0.02 | Energy Produced (J) | Energy Produced per grams (J/g) | Cashew | T1 | 200 | 5 | 0.31 | 4180 | 13483.87
LabQuest 34 Vapor Pressure and Heat of Vaporization Vapor pressure or scientifically called equilibrium vapor pressure is the condition wherein the vapor from a liquid over the same liquid in a sealed container is at a point wherein the amount of gas leaving the liquid equals the amount of gas re-entering the liquid from the vapor above the liquid. However there is a mathematical between temperature and vapor pressure, and the Clausius-Clayperon equation attest to this relationship. Clausius-Clayperon equation - ln P = - [∆Hvap / R][1/T] +C The intent of this experiment was to determine the temperature/vapor pressure relationship using the volatile liquid ethanol, CH3CH2OH; and calculate its heat of vaporization. This data was collected over a range of temperatures, 22.4° C to 34.9° C. It was intentional that the temperature remained under 40° C less the pressure inside the Erlenmeyer flask got high enough to pop the stopper out of the Erlenmeyer flask. Materials and equipment: MATERIALS Labquest 20 mL syringe Labquest App two 125 mL Erlenmeyer flasks Vernier Gas Pressure Sensor ethanol, CH3CH2OH Temperature Probe 400 mL beaker rubber stopper assembly 1 liter beaker plastic tubing with two connectors hot plate Procedure: The apparatus was set up as requested by the Lab quest 34 handout and an initial pressure reading of 101.6kpa was obtained at room temperature, 22.4° C. Then the Erlenmeyer flask and the sensors were conditioned to the water bath by holding the flask down into the water bath to the bottom of the white stopper for 30 seconds, and then the valve on the white stopper was closed to keep the ethanol vapor from leaving the container at any time during the experiment.