Once 3-4 readings for the solution were collected, the 2M NaOH was added to the solution. The lid was quickly replaced in order to prevent heat from escaping and not being recorded by the temperature probe. The cup was swirled until the temperature reached a peak and began decreasing. After the 180s had passed, data collection ended. The solution was discarded into the waste bin, and the materials were washed.
To start gram staining, I slightly pour crystal-violet all over the slide and let it sit for 30 seconds before wash it off with water. Next, I dye the Unknown with Gram’s iodine to create a complex only have on gram positive. The slide is rinsed by water after 30 seconds. Decolorization is the next step of the whole process. I let the alcohol flow on 45-degree angle slide within 15 seconds and wash it with water to remove colors on the surface.
Finally the hexane layer was washed with 100 ml water and then evaporated to dryness with a vacuum rotary evaporator. The concentrated extract was then passed through a chromatographic column (30 cm x 10 mm i.d) containing 2 g florisil (lower) and 1 g sodium sulphate (upper) which is pre wetted with hexane: acetone (1:1). OCPs were eluted with 25 ml hexane: acetone (1:1).The solvent was evaporated using rotary evaporator and final volume was adjusted to 5 ml, which is used for GC analysis. All the sediments were analyzed for HCH and
A stir bar was also added to the solution. The glass stirring rod from previous steps was used to remove pieces of Cu that formed on the Al wire, so that more Al surface would be exposed. A steam bath was prepared with 50 mL of deionized water, the glass rod was used to remove as much copper from the aluminum wire as possible, and the Al wire was then disposed of in the solid waste container. The mass of an evaporating dish was recorded, and the Cu was transferred on to the evaporating dish. Water was removed from the dish, and the Cu was then washed thrice with 5 mL deionized water, and decanted between washings.
The difference in this chemical and physical properties will aid in their separation. Processes like solubility, gravitational filtration and recrystallization will be used to separate the substances present in Panacetin. The melting and boiling point of the substances will help in concluding on which of these compounds will be presented at the end of experiment. Procedure and observation The Panacetin content was weighed approximately 3.0493g and transferred to the Erlenmeyer flask; 75ml of dichloromethane (CH¬2CL2) was added to the content. The dichloromethane (CH2Cl2) dissolved the sucrose, leaving the active unknown agent and aspirin behind.
Repeat the experiment. The cola drinks were titrated using the following method: Prepare the beverage in a 250ml volumetric flask. Use a funnel to facilitate the process. Place the beaker on a hot plate so that it boils and place a watch glass on top to prevent the carbon dioxide from the atmosphere getting dissolved in the cola. Once the cola starts to boil, continue to boil it for another 10 minutes so that the carbon dioxide is removed.
Once this point was reached, the timer was stopped and the time was recorded in Data Table #1. The same steps involving the addition of Na2S2O3 were repeated for Wells #2 and #3, using 2 mL of Na2S2O3 in each. The final times for each well was recorded in Data Table #1 in the appropriate blank. Once the first trial was completed for the first three experiments, a second trial was completed in Wells #4, #5, and #6 using the same procedure in order to increase accuracy. After each trial was conducted, each of the wells were emptied into the designated waste container and dried using a paper
First, 50 mL of the sample was placed into a 250 mL Erlenmeyer flask, and onto a stirring plate. Then, the pH of the solution was measured and adjusted to be within the range of 4 and 6, using nitric acid and sodium hydroxide. After the pH was optimal for the experiment, a single mL of indicator- acidifier reagent was added to the sample. Then, 50 mL of mercuric nitrate was place into a burette and titrated with the sample until the color of the solution turned from blue to purple. The volume of titrant used for the reaction to reach endpoint was recorded.
Purpose: The purpose of this lab is to titrate an unknown solid acid (KH2PO4) with a standardized sodium hydroxide solution. After recording and plotting the data, the acid’s equivalence point will be recorded once the color changes. Using the equivalence point, the halfway point will be calculated, which is used to determine the acid’s equilibrium constant. The acid’s calculated equilibrium constant will be compared with the acid’s established pKa value. Eventually using the NaOH and the acid’s consumed moles, the equivalent mass will be determined.