Pour the contents of one of the test tubes into the other and a reaction should occur and you should see a white precipitate of barium sulfate form. Then, centrifuge it for 1 minute. On the side, weight a boiling test tube containing 2 boiling chips. When the separation is complete, remove the small test tubes from the centrifuge and decant the supernatant into the boiling test tube. Add 1 mL of deionized water to the small test tube containing the precipitate and mix it and centrifuge it for 60 seconds.
The following data were obtained when a sample of barium chloride hydrate was analyzed as described in the Procedure section. Calculate (a) the mass of the hydrate, (b) the mass of water lost during heating, and (c) the percent water in the hydrate. Mass of empty test tube 18.42 g Mass of test tube and hydrate (before heating) 20.75 g Mass of test tube and anhydrous salt (after heating) 20.41 g. Mass of the Hydrate is 2.33g. Loss (H2O) is 0.34g. Percent H2O in Hydrate is equal 0.34/2.33=14.6% 3.
A graph for the data was also set up with time on the x axis in .5 second intervals and temperature on the y axis. The first task required the freezing point of pure p-xylene be determined. This was done by pipetting approximately 2ml of p-xylene into a polypropylene test tube. The dry thermistor probe was inserted into the p-xylene test tube which was then inserted into an ice water bath. The temperature probe was used to stir the p-xylene and ensured an accurate reading.
Abstract The focus of this experiment was to analyze the kinetics of a nucleophilic substitution. A mixture of 0.3622-M 1-bromopropane and 0.3622-M potassium hydroxide in an 90:10 ethanol/water solvent provided the reactants for a SN2 reaction to occur in a temperature controlled bath at 50.0˚C. The disappearing reactant was found by titrating timed aliquots during the reaction and then measuring the concentration of hydroxide. The k-value was found to be 0.0202 M-1Min-1. Using the linear form of the Arrhenius equation the activation energy was calculated to be 19.9 kcal/mol.
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.
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
Materials: 3 beakers Thermometer 3 Alka-Seltzer tablets Stopwatch Mortar and pestle Source of hot water Ice cubes Graph paper Procedures: Hot water- Run water from the hot tap until it is hot as possible Fill beaker with 80 mL of hot water Use thermometer to take temperature of water. Record in data table. Remove 1 Alka-Seltzer tablet from package Drop into the water. Measure the time it takes for the tablet to completely dissolve. BE READY WITH THE STOPWATCH.
Nest one Styrofoam cup in another 11. Obtain an exact mass of tap water (45-50g) to serve as cold water 12. Put a magnetic stirrer in the bottom of the calorimeter 13. Secure temperature probe to a ring stand 14. Place temperature probe through hole in cardboard lid and position probe about 1cm above bottom of calorimeter 15.
Reactions Lab David Vaghari INSTRUCTOR: Dr. Chernovitz Monday, July 23, 2012 Oxygen Production Introduction In this lab, potassium chlorate will be decomposed producing oxygen gas and potassium chloride. The hypothesis is that the reaction will yield 3.916 grams of oxygen gas. Materials Test tube 10 grams potassium chlorate Bunsen burner Procedure Step 1. Obtain a test tube, place a 10 gm of potassium chlorate. Step 2.
Experiment Colligative Properties & Osmotic Pressure Karen Curry 1/19/2014 1:00pm Abstract The purpose of this experiment is to understand and compare the difference of the freezing points between pure solvents in a solution and a non-volatile solute. Secondly, osmosis is demonstrated in a permeable membrane in this case a dialysis tubing and a less permeable membrane with a much harder shell like the egg. Experiment and Observation Starting with Part I of this experiment I gathered together all my items I needed. Small rubber band, salt, tap water, distilled water, 1/8 teaspoon measuring spoon, crushed ice, beaker 100 mL plastic, stopwatch-digital, test tube 13 x 100 mm, digital thermometer, well plate-24. First I made a water bath by filling the 100 mL beaker with cool tap water.