Hydrochloric acid was then added to the solution until the bubbles stopped in order to completely get rid of all of the zinc. Next, we used vacuum filtration to filter the copper out of the solution. We drizzled alcohol and acetone over the copper to help it dry faster. Once it appeared dry, we weighed the copper and filter paper. When we subtracted the mass of the filter paper, the mass came out to 1.312g.
Introduction The purpose of this lab is to determine the normality of an unknown base using a volumetric titration. The volumetric titration used for this experiment consisted of a standard acid called potassium hydrogen phthalate (KHC8H4O4) titrated with a weak unknown base. An acid-base indicator called phenolphthalein is used in order to view the reaction proceeding to completion. The indicator allows visualization of the acid changing colour when the solution has reached the end point. The normality of the unknown base is calculated after the solution has reached the end point.
0.1 M silver nitrate was added to the anion solution and a precipitate was formed. Dilute HNO3 was then added dropwise to the precipitate until it became acidic. The supernatant was decanted out and the precipitate remained. 5 mL of distilled water was added to the centrifuge tube with the precipitate. 6 M HNO3 was then added dropwise to the precipitate until the solution was acidic.
Analysis of an Aluminum-Zinc Alloy Objective: The objective of this lab was to analyze the alloys of aluminum and zinc to see how not all compositions correspond with stoichiometric ratios. Procedure: A suction flask, large test tube, stopper assemblies and a sample of Al-Zn alloy was obtained and figure 1 was replicated. Then a gelatin capsule was obtained an weighed in an analytical balance, the alloy sample was placed in the capsule and the weight was measured again. The mass was between .1000 and .2000 grams more than the original weight. The suction beaker was weighed then filled with water and reweighed.
The purpose of this experiment is to record its physical properties and how the reaction reacts.. During the lab, my hypothesis toward this experiment was that the reactants was going to be successful and turn black. Materials: -Copper Sulfate -Zinc -Zinc Sulfate -Hydrochloric Acid Equipment: -Two test tube -Wood Splints -Graduated Cylinder -Matches -Two Watch Glasses -Goggles Data/Results: Observations: Observation 1 Copper Sulfate Liquid and it turned into a blue green color. Observation 2 Zinc was placed The solution starts to become silver, hard and rock lie. Observation 3 Copper acid was added. The solution starts to turns into a black color.
Gently stir the pellets until the acid is dissolved by shaking the the apparatus. Lift the calorimeter lid and wash out its contents and the thermometer. Repeat this experiment using 50.0 mL of 1.0M acetic acid. Repeat experiment using 25.0 mL of each 2.0M sodium hydroxide and 2.0M acetic acid. Data Table(s): Reaction equation Mass of solid NaOH Initial Temp.
Close the top 5. Put in Thermometer 6. Record starting temperature 7. Use the stirrer to help stir the water and mix it with the sodium chloride 8. Wait until the temperature stops increasing and record the final temperature Data: When the sodium chloride was added to the water, the water started to heat up.
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.
Extraction and Drying: Using a separatory funnel, the cooled filtrate was extracted with 10ml of methylene chloride. After shaking our mixture, we broke and dried our emulsion by slowing passing the lower layer through a cotton ball layered with anhydrous magnesium sulfate. The extraction process was repeated 2 more times for maximum collection of the organic layer. Distillation: The extracts were poured into a 50ml round bottle flask and connected to a simple distillation apparatus. To obtain the caffeine, the methylene chloride was removed from the extract, leaving us with our solid caffeine residue.
When the compound had completely dissolved, 4-5 drops of ammonium hydroxide (NH4OH) was added to the solution in order to create a precipitate. As the NH4OH was added the solution became cloudy. Slowly 25mL of dimethylglyoxime (C4H8N2O2 or DMG) was added to the solution while stirring. As soon as the DMG was added it immediately turned pink and formed the Ni(DMG)2 precipitate. Below is the reaction equation for this.