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.
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.
Lab 4: Determination of Percent by Mass of the Composition in a Mixture by Gravimetric Analysis Introduction Thermal gravimetric analysis is used to determine the percent by mass is used to determine the percent by mass of a component in a mixture. When a mixture is heated to an appropriately high temperature, one component in the mixture decomposes to form a gaseous compound. The mass of this particular component is related to the mass of the gaseous compound. In this experiment, the percent by mass of sodium hydrogen carbonate (NaHCO3) and potassium chloride (KCl) in a mixture will be determined. 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.
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
17. Press START and turn on the stir bar. 18. After 10 seconds have elapsed, add hot water sample 19. Press STOP when the thermograph stabilizes 20.
Hydrate Lab The purpose of this lab is to analyze the percent water in a crystalline hydrate and to indentify the hydrate from a list of possible unknowns. The solid hydrate will be heated to remove the water, and the percent can be found by measuring the mass of the solid before and after heating. The hydrate will be indentified by comparing the percent water in the hydrate with the percent water calculated for the possible unknown. Before the lab there are pre-lab questions: 1. Describe the three general safety rules for working with a Bunsen burner.
Materials: Safety Goggle Laboratory Apron 60-cm3 syringe with end cap 2 utility clamps Ring stand and ring Wire gauze 600-mL Beaker Thermometer inserted into spilt stopper Bunsen Burner Air pump w/ pressure gauge Balance 1 L Graduated Cylinder (or assume syringe vol. = 10mL) Pressure Bottle Syringe, 10mL, with tip cap Procedures: Part 1: Charles’ Law 1. Remove end cap of 60-cm3, fill with air to 20-cm3 2. Put the cap back on, place syringe in utility clamp *MAKE SURE IT’S SECURE* (don’t cover volume scale with cap) 4. Add 400mL of room temperature water to a 600-mL beaker 5.
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.
Lab 4 – Energy Sources and Alternative Energy Experiment 1: The Effects of Coal Mining |Table 1: pH of Water Samples | |Water Sample |Initial pH |Final pH (after 48 hours) | |Pyrite |.6pH |.7pH | |Activated Carbon |.6pH |.8pH | |Water |.6pH |.7pH | POST LAB QUESTIONS 1. Develop hypotheses predicting the effect of pyrite and coal (activated carbon) on the acidity of water? a. Pyrite hypothesis = If pyrite is added to water, then the acidity of the water is neutral. b. Coal (activated carbon) hypothesis = If coal or activated carbon is added to water then the acidity of water is basic.
Title and number: 1-31 Molecular Mass of a gas Lab report number 2 Purpose: The purpose for doing this lab is to learn how to measure gas by using volume and water. Also to proved whether Avogadro hypothesis is true or not by using these characteristics: mass, volume, pressure and temperature that will allow you to calculate the molecular mass of any gas. Principle: The new lab technique that we used is the displacement of water. We did this by putting water in a tank, placing the graduated cylinder in the water and get the opening end of the graduated cylinder in the water while letting the water to enter the cylinder without getting any bubbles in it, because having bubbles in the water would increase the error percentage of our results. Then, stand the cylinder upside down after measuring the lighters and then, placing the lighter near the cylinder while releasing butane into the cylinder.