In most cases, water was used as the solvent to the reaction mixture to dissolve the inorganic compound. The organic compounds will be separated from the aqueous mixture by extraction with an organic solvent that is immiscible with water. Therefore, they will form two layers when they are mixed together. The denser liquid will form the bottom layer. (Conversely, miscible liquids are soluble in each other.)
1) Percentage yield experiment: First we measured 20cm3 of sulphuric acid into a beaker using a measuring cylinder, this will help us determine the percentage yield at the end of the experiment. We then heated the beaker containing the sulphuric acid using a Bunsen burner in order to heat it up for the copper oxide to mix with. We then weighed out 1.02g of copper oxide and added it to the acid and stirred it whilst doing so, we did that until the liquid turned blue, this proves that the chemicals have mixed together. We then weighed this liquid which will help us determine the percentage yield. We then filtered the liquid off which gave us the amount we obtained.
Methods: Weight a clean, dry, porcelain evaporating dish on the electric balance and record this mass on an appropriate data table. If the crucible needs to be washed before use, then heat the crucible in the Bunsen burner flame for a few minutes and remove any residual water. Then allow it to cool before continuing. Fill the crucible about 1 gram with the hydrated salt and reweight. Assemble the ring stand, ring, clay triangle, and Bunsen burner
In this reaction NaOH was added to the Cu(NO3)2. The solution developed a precipitate which made the clear solution become cloudy and uniform in color (blue). The physical color change was demonstrated through the formation of the precipitate. The third step was the formation of CuO. In this reaction, the Cu(OH)2 product was heated on a hot plate and stirred continuously until the solution became colorless and a dark precipitate formed.
Two clear solutions are mixed, producing a new clear solution. Then, after a period of several seconds, the solution turns dark blue. As mentioned, chemical kinetics measures how fast a reaction is occurring. To perform the iodine clock reaction in this science fair project, you will mix potassium iodide, hydrochloric acid, starch, thiosulfate and hydrogen peroxide. The time it takes for the reaction mix to turn blue will be measured with a stopwatch.
The solution was discarded into the waste bin, and the materials were washed. The second reaction in Part B, sodium hydroxide and ammonium chloride, began by saving the data from the first reaction and setting up the LabQuest to new data collection under the same conditions as the first reaction. The cups were restacked and placed in the beaker. Using a graduated cylinder, 50mL 2M NaOH was added to the cup. The cup was then covered and the temperature probe inserted.
Sodium borohydride was added in slow portion as the reducing agent, dissolving the precipitate into a yellowish lime solution. Glacial acetic acid and acetic anhydride were added to the mixture while refluxing, which converted the lime colored solution into a clear mixture. The flask was cooled in an ice bath and the solution
The electro pores reseal spontaneously and the cell can recover. The formation of electro pores depends upon the cells that are used and the amplitude and duration of the electric pulse that is applied to them. Electric currents can lead to dramatic heating of the cells that can results in cell death. Heating effects are minimized by using relatively high amplitude, a short duration pulse or by using two very short duration pulses. In terms of mammalian trans genesis, electroporation is an effective method of introducing exogenous DNA into embryonic stem (ES) cells.
On the second day of incubation, the plate was removed from the incubator and placed over a hot plate heating Iodine solids. The smoke of the Iodine stained the plate to display the presence or absence of a halo around the bacteria 2.12 Lipid Hydrolysis This test was done by making a single line streak inoculation on a tributyrin agar plate and allowing incubation. After the incubation period, the plate was observed for the presence or absence of a halo around the bacteria. 2.13 Gelatin Liquefaction A gelatin deep was deep stabbed and incubated. After incubation the tubes were placed in 4ºC for 30 minutes.