Then 8.0g of copper sulfate crystals were placed inside the beaker and the mass was recorded for the actual crystals. 50 mL of water was added to the beaker with the crystals. The ring stand was set up with the wire mesh on it and one partner should place the mixture in the beaker on it should be heated without letting the mixture boil. Stir the mixture and heat until the crystals are dissolved. While one partner does this, the other should obtain 1.5g of iron filings in a measuring cup and records the mass. Then the iron filings should be added small amounts at a time to the heated solution. Stir continuously until all the mixture is added to the beaker. Then it sat for 10 minutes and observations were recorded. Record the mass of a filter paper and set up a filtration apparatus with the filter paper in a funnel over an Erlenmeyer flask. Decant the liquid through the paper slowly trying not to allow any solid to get on the filter paper. Then with de-ionized water, rinse your solid in the beaker and let the solid settle then decant the liquid. Repeat the washing twice more and in the last time guide all the solid into the filter paper. Then place the filter paper on a watch glass and then into a warm oven to dry. After it is cool, record the mass of the watch glass, filter paper and solid. If there is not enough time to cool, you may have to do it the next
Once these steps were completed, the cuvette was placed into the spectrophotometer to test for phosphate, nitrate, ammonia, and turbidity. Inside the spectrophotometer, a light was shot through the sample to detect the contaminant. The first ever spectrophotometer was only developed to calculate pH levels and never used wavelength to calculate the abundance of chemicals within a sample. After many years of developing the spectrophotometer, a glass prism was installed. This allowed the spectrophotometer to use light wavelength to calculate the concentration of chemicals within a sample. The light was able to read the preferred contaminant because a reagent attached to each molecule, and the light was reflected back instead of being shot through the sample. This gave the concentration of each contaminant in the sample. In each machine, there was a different light wavelength programmed to shine through the sample to detect the different contaminants. This was done to get an accurate measurement of phosphate, nitrate, and ammonia within the sample. Turbidity was also measured using the spectrophotometer, but there was no reagent added. The turbidity was calculated by testing distilled water first and comparing it to the turbidity of the BSR water.
The procedures for experiment A, B, and C all start the same. The first step is to put on goggles and get the data collection device set properly. The labquest needs to be plugged into the colorimeter accurately so that a click is heard when putting it in. The labquest needs to be reading digitally and the colorimeter needs to be set to 635 nm. Then shake the chloroplast solution and take a clean cuvette and fill it with 3 mL of distilled water, 3 drops of the chloroplast solution, and cap it. This is used as a blank to calibrate your labquest. Double check that the labquest is reading absorbance, this assures that the colorimeter is plugged into the labquest accurately. Insert the blank into the colorimeter and hit the calibration button. Take out the blank and empty it. The labquest is now set to experiment with. Make sure that the heat bank is set in front of the lamp and that the lamp is on. The cuvette must be placed on the opposite side of the heat bank in the path of light in the box so that no other light can interfere with the experiment.
Where A is the initial absorbance when the experiment first starts, l is the path length of the cuvette (2.54 cm), and [CV]t is the initial concentration of crystal violet.
Obtain a ring stand, ring, and wire clay triangle to heat the sample. Measure the mass of a crucible and its cover. Measure the mass of the copper chloride hydrate. Record both masses. Next, pour the hydrate into the crucible and measure and record the mass with the crucible lid on. Place the crucible on the clay triangle, tilting lid slightly away from you to prevent inhaling or coming in contact with any fumes that the compound may
After this, the solution was poured into a volumetric flask just about to the 1dm3 line and then it was left there to cool to the same temperature as the room before filling precisely to the 1dm3 line with distilled water. The molar mass of CuSO4.5H20 was 249.5 so that means 249.5g of copper sulphate was needed to dissolve, in order to make a standard solution, into 1dm3of distilled water. Following this, a linear dilution of the CuSO4.5H2O was made in order to be used to make a calibration curve after using the colorimeter to write down the absorbance of each sample. A linear dilution is diluted with distilled water in order for it to make the concentration weaker and weaker. For this investigation, the dilutions made ranged from 0.01 to 0.1 M/l . It was essential to only make up 10cm3
Put approximately 9-10(g) copper ore into beaker. Use spatula to break up any large pieces. Next add 17ml H2SO4 (aq) (hydro sulfuric acid) to the beaker. Began mixing until all or most traces of blue dissipate; or the copper ore will no longer dissolve (should appear as a milky liquid). Next use pipette to and remove solution and divide solution into 2 individual test tubes then Place test tubes into centrifuge and run centrifuge for 1 minute. Remove from centrifuge machine Fill a cuvette with the clear solution from the test tube making sure not to disturb the sediment at the bottom. Note the solution should bluish in tint Final place the cuvette in the colorimeter. Then record data and calculate in results section.
Incorporation of assay controls included setting up a spectrophotomer and running the chart recorder with a full-scale deflection before the start of the assay. The set recorder had a corresponding value of 1 for the change in the absorbance. Therefore, prior testing was done to observe whether a change occurred in the readings. This helped to indicate that the results were valid, as they could have been affected by a fault during the setting up of the spectrophotometer. On the other hand this was considered as one of the controls for the experiment. Nevertheless, a new cuvette had to be used for each assay.
Begining by labeling 7 different 2.0 ml tubes 0 thru 6 for each compound. Then add 1ml of extract to tube 0. Then add 0.5 ml of DMSO to tubes 1 thru 6. Now make a 1:2 serial dilution from 0(pure extract) to 6(1:16)
The wavelength of the light should be a different color from the solution’s color. This is because if the color of the wavelength of the light is the same color as the solution’s color, then the color would not be absorbed. The only way that a solution can absorb a color is if the color of the light’s wavelength is its complementary (opposite) color. The color of the light chosen for this experiment was blue because the wavelength was set to 430nm, which corresponds to blue's wavelength. The color of the FeSCN2+ complex ion is blood-red.
From this graph and chart we can see that the higher the concentration the higher the absorbance, all the different concentrations were tested at the same wavelength (625nm). Also we can determine our unknown substances concentration by using the absorbance we got for it. The red dot on the graph followed by the line towards the horizontal axis indicates that the concentration of fast green was 34% or 5.1x10-3.
When you use a spectrophotometer you should not set the wavelength of light to be the same color of the solution. This is because if you set the wavelength to be the same color of the solution then no light will be absorbed. The reason why no light will be absorbed is because the color you see is the wavelength of light that is being reflected so you must set the wavelength to be the complementary color. The wavelength of light that was chosen for the lab was 450nm which coincides with a very dark blue color. The reason why choosing a dark blue makes the most sense for this experiment is because the color of the FeSCN2+ ion was blood red.
The same solution of 0.5 ml BSA was then added from test tube 1 to the test tube 2 after being properly mixed, and from test tube 2 the solution was being added to test tube 3, and so forth all the way up to test tube 5, with the same exact procedure. From the last tube, we then disposed the 0.5 ml solution. After above procedures, we now labeled another test tube “blank”; 0.5 ml blank distilled water was purred into the tube with the serial dilution of 1:10. We also had a tube C labeled “unknown” with the same 0.5 ml of solution. And after adding 5ml of Coomassie Blue to each tube (1-5) and to the blank, the result of absorbance was read at 595 nm.