Immediately transfer the metal into the calorimeter cup so that the water covers the metal. Cover the calorimeter cup with its lid ASAP. 9. Carefully insert the thermometer through the small hole in the lid. Stir very slowly with a stirring rod and record the highest temperature reached by the water in Data Table 2.
After a few minutes the acid dissolved the capsule creating a black foam that then turned into a clear liquid again. Once the liquid was clear again, the clamp was closed and the beaker was weighed. The temperature of the water was also taken. This was then repeated again for Trial 2 with a new capsule. Specialized Chemical Techniques: The specialized technique used in this experiment was
Sodium Hydroxide + Hydrochloric Acid Sodium Chloride + Water NaOH(aq) + HClaq → NaCl(aq) + H2O(l) Variables Independent The independent variable of the experiment was the amount of sodium hydroxide that we added to the acid. To keep the variable controlled we would measure 1 ml of the sodium hydroxide and pouring that to the hydrochloric acid. Dependent The dependent variables of the experiment were the temperature and the pH number of the mixture. To control the pH and temperature use the electronic probe and data logger. Controlled The controlled variables of the experiment were: A.
After the solid was dissolved, 230mg of methyl salicylate was added using a graduated pipet to the NaOH solution. A white solid was soon formed. And a boiling stone had been placed in the flask to prevent bumping of the solution when it was heated. After grease was lightly coated to the lower ground glass joint of the condenser, a water-cooled reflux condenser had been attached. The reflux apparatus was place in the aluminum block.
The mixture was decanted again in to the same beaker. Next, we added boiling chips to the liquid and evaporated the solvent over the hot plates under the hood. After the solvent was evaporated and the flask was cooled, we used a spatula to remove a small amount of the crude product and took its melting point. We determined the melting point range of the sample to be 43.0-46.0 degrees Celcius.The crude product was yellow colored when it was warm and orange in color when cooled and sticky. We then recrystallized our sample using 5 ml of warm acetone that was heated on a hot plate under a hood.
The release button on the lighter is pressed and held until approximately 90 ml of water is displaced from the cylinder; the level of the water in the cylinder should be level with the water in the trough. The temperature of the water is taken and the lighter is reweighed. All data is recorded and then this experiment is repeated three times, using all the same material. Data and Observations: As the water is displaced from the cylinder, bubbles continuously floated to the end of the cylinder as the water level went down. See Table 1 for all the recorded results.
To obtain the caffeine, the methylene chloride was removed from the extract, leaving us with our solid caffeine residue. Sublimation: We purified our solid caffeine through sublimation. By constructing a side-arm test tube apparatus, we vaporized and condensed the caffeine using a Bunsen burner. Upon cooling, the apparatus was carefully disassembled and the sublimed caffeine was scraped off of the test-tube collection surface and weighed. The melting point range was then determined by utilizing a melting point apparatus.
You will observe in this experiment some of the characteristics of the alkaline earth metals discussed here and will write balanced equations for all reactions. Purpose: Investigate some reactions of some group 2 elements and gain some insights into the properties of these alkaline earth metals. Equipment: (pg 131) Materials: (p 132) Safety: • Avoid skill and contact with your skin • Tie back long hair • Wear safety goggles Procedure: (record all data in the observations and data section) Part A 1. Pour 5 ml of distilled water into a clean and dry test tube and put the test tube into on the test tube rack. Add a calcium turning to the water in the tube.
SAFETY * Wear goggles at ALL TIMES * Be careful not to ingest any chemicals * Handle boiling water with care * If any chemical should come in contact with your skin rinse IMMEDIATELY * Report any and all accidents to your teacher/advisor PROCEDURE 1. Attach a utility clamp to a 125mL Erlenmeyer flask. Submerge the flask as deep as possible into a 600mL beaker on a hot plate. Pour water into the beaker around the outside of the flask; be sure to allow enough splash area for the boiling water so it does not fly out of the beaker and onto you. MAKE SURE NO WATER GOES INSIDE THE FLASK.