This was allowed to cool to approximately 55ºC and ethidium bromide (10mg ml⁻¹) was added to a final concentration of 0.5 μg ml⁻¹. 4. The gel was poured to a depth of about 5 mm, taking care to avoid bubbles and was allowed to solidify for 30 mins at room temperature. 5. The tape was removed and the trough containing the
After the mixture was heated, there was solid on the bottom and liquid on the top of the flask. The set up was let cool to room temperature. Next, we decanted the mixture in to a clean 100 ml beaker. We rinsed the remaining solid with 10 ml of DCM and swirled the mixture. The mixture was decanted again in to the same beaker.
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
1.0 mL of conc. sulfuric acid was slowly added and the mixture was allowed to genly boil under reflux for about 75 minutes. After reaction, the mixture was allowed to cool and was transferred to a beaker containing 30 mL of water. 10% sodium carbonate solution was added until gas was no longer evolved and the pH was around 8. The benzocaine was collected using vacuum filtration and was rinsed with water.
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.
The more active the metal the more basic it’s saturated hydroxide solution. The sulfate compounds of alkaline earth metals show decreasing solubilites as you go down a group. This characteristic is used as a means of separating and identifying metallic ions in a group. Carbonates are pretty insoluble. 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.
After which time, 2.1 mL of 30% hydrogen peroxide was added slowly followed by sodium hydroxide until a pH of 8 was observed. 20 mL of H20 and 10 mL diethyl ether were added to the flask. The contents were separated and the aqueous layer was rinsed with four 10mL portions of ether followed by 15 mL of sodium bicarbonate. The ether layer was dried with granular magnesium sulfate and then the solvent was removed by evaporation under reduced pressure. Lastly, the final product was analyzed by mass spectrometry and HNMR.
Each organic extract is then dried over anhydrous calcium chloride pellets and evaporated to dryness. The extract is then wet with a minimal amount of dichloromethane and a sample of each is obtained and mixed together with 200 mg of alumina and again evaporated to dryness. This mixture is then placed in the prepared chromatography column and eluted with hexanes until the yellow β-carotene band is collected. The solvent is then switched to a 90/10 mix of hexanes and acetone to speed up the elution of the more polar lycopene band, which is also collected in its own flask. Each of these samples is evaporated to dryness and rehydrated with a minimal amount of dichloromethane.
Transfer the extracts to a simple-distillation assembly and distill off all but 10 mLof the solvent on a steam bath. Save the recovered solvent. Evaporate the combined solutions to dryness on a steam bath or hot-water bath in a hood. To purify the crude product, dissolve it in about 5 mL of acetone by warming the mixture on a steam bath; add dropwise just enough mixed “hexanes” to turn the warmed solution faintly cloudy; then allow the solution to cool and allow the product to crystallize. Collect the green-tinged crystals on a small vacuum filter and wash them with a little mixed “hexanes.” The melting point of caffeine reported in the literature is 236°.
The equation for the reaction is known as: Metal + cold water [pic]hydrogen(H2) + metal hydroxide (MeOH) The reaction is very exothermic and had the tendency to allow the hydrogen to ignite a fire. Sulfuric acid is a very strong dehydrogenation agent which allows it to be a danger to people. We had tested this on sugar instead of an actual human being. The chemical reaction is very exothermic and causes the intense dehydration of the sugar. The Sulfuric acid is a catalyst for the reaction.