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
4) Ignoring step 3, after step 2, you can take the solution that you have created and pour it into a 100 mL beaker. Once the solution is in the beaker, turn on the conductivity tester and gently place it in the solution (try not to touch the bottom of the beaker). Record the results. 5) Now, take the beaker with the solution already inside and place it on a hot plate. Turn on the hot plate to a medium heat.
Observing Changes – Materials & Procedures Materials Water Copper (II) sulphate (Powder) Copper (II) sulphate solution Iron nail Sodium carbonate Hydrochloric acid Magnesium ribbon Flame (candle) Sugar Aluminum foil Test tubes Test tube rack Tongs Medicine dropper Spoons Beakers Safety goggles Scoopulas Procedures Water and Copper (II) Sulphate Procedure 1. Add a small amount of solid copper (II) sulphate to a test tube with a scoopula. Record the physical properties. 2. Write a hypothesis on what you think will happen when water is added.
Hypothesis: Using melting points can help determine the difference in total carbon atoms and branches between two or more compounds. Materials List: 1 Spoon 1 Paper towels 3 Small rubber bands 2 Clean sheets of paper 1 Beaker, 100 mL, glass 1 Burner-fuel 1 Burner-stand 1 Goggles-Safety 1 Magnifier, dual 1 Thermometer-in-cardboard-tube 1 Capillary tubes-3/pack 1 Tetracosane Crystals - 0.2 g in Vial 1 Tetradecanol Crystals - 0.2 g in Vial Procedures: Prior to beginning the lab exercise, read the instructions carefully. Begin by setting up a derivative melting point table to collect the data accumulated during the exercise. This lab uses heated water so be sure to follow safety procedures carefully. While conducting this laboratory experiment, be sure to use minimal amounts of each substance in order to create the habit of using only the amount necessary.
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.
While stirring, 6 M NaOH was added drop-wise until the solution became basic, turning red litmus paper blue. A total of 3.84 mL NaOH was required to achieve this; the resulting solution appearing dark blue with cloudy precipitates. The solution was then heated gently atop a hot plate to catalyze the next reaction, with care taken to assure all residue was kept off the walls of the beaker. Heating continued until the reaction reached completion and the solution slowly changed from blue to a dark green and finally black. At this point the heat was turned off to allow the black solid in the beaker, CuO, to settle to the bottom.
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.
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.
Prelaboratory preparation: Read pages 1 – 30 and 45 – 54 of the lab text. You may disregard the microscale distillation procedures of TECH 0704. Answer in your laboratory notebook the Safety Quiz on pages 11 – 12 and the Prelab Questions 1, 2a, 2b, 3 -5, pp. 67 - 68. EXPERIMENT: TECH 0704, Distillation, macroscale technique only, simple and fractional: Substitute a mixture of 25 mL ethanol and 25 mL water for the toluene/cyclohexane mixture.
After all the acid has been completely added and the reaction has stopped, use a pipette to add a few extra drops of acid into the beaker until the reaction stops. 7. Place the beaker on a hot plate and heat on a high setting to boil off the water. WARNING: THERE WILL BE A SMALL AMOUNT OF HYDROCHLORIC ACID BOILING OF THE MIXTURE. DO NOT PLACE YOUR FACE DIRECTLY ABOVE THE BEAKER.