Nt1310 Unit 9 Final Lab Report

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.

To begin the experiment, start by grabbing five cuvettes and labeling them one through five. After they have been labeled, add 2 mL of water to cuvette one, and 1mL of water to cuvette two through five. Then add 1mL of Catechol in cuvettes two through five. Because of the time considerations, test two cuvettes at a time. To do this, add 5 drops of Parahydroxybenzoic acid to cuvette two and 10 drops to cuvette three. Afterwards add 5 drops of Catechol Oxidase to cuvettes one through three. Blank out the spectrophotometer with cuvette one containing the water (H20). Then test the absorbency of cuvette two and three checking them every two minutes for twenty minutes, record your results. After those cuvettes have been tested, cuvette four and five need to be tested. Begin this by adding 15 drops of parahydroxybenzoic acid to cuvette four and 15 drops to cuvette five. Add in 5 drops of Catechol to cuvette four and five. Blank out the spectrophotometer again with cuvette one. Proceed to test cuvette four and five by checking the absorbance every 2 minutes for 20 minutes, record your

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

Scientists use an instrument called a spectrometer to quantitatively determine the amount of light absorbed by a solution. The primary inner parts of a typical spectrometer are described below. The spectrometer has a light source that emits white light containing a vast mixture of different wavelengths of electromagnetic radiation. The wavelength of interest is then selected using a monochromator (“mono” meaning one and “chromate” meaning color) and an additional exit slit. The separation of white light into different colors (wavelengths) is known as diffraction. The selected light then reaches the sample and depending on how the light interacts with the chemical compound of interest, some of the light is absorbed and some passes straight through. By comparing the amount of light entering the sample (P0) with the amount of light reaching the detector (P), the spectrometer is able to tell how much light is absorbed by the sample.

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.

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 purpose of this lab was for the student to get involved with his or hers new lab kit as well as being able to know, identify and use each other tools provided in the kit. Another key learning aspect of this lab is to teach the student how to measure properly the many units in the SI system. I will be using laboratory dilutions, measurements, and weights to then calculate using algebraic formula.

Experimental Methods: Experiment 1- Absorbance Analysis Collect four cuvettes and add approximately 2/3 of the allowed volume to one of the cuvettes with distilled water. Find the spectrophotometer and insert the cuvette filled with the distilled water into the spectrophotometer. It is essential that the cuvette is inserted correctly: lining up the triangle on the cuvette with the triangle on the

2 mL of Rhodamine B in a graduated cylinder 3. Add 6 mL of water to graduated cylinder 4. Fill vial with water to zero out the Spectrophotometer 5. Add the Rhodamine B and water dilution to vial 6. Heat the solution to around 50 degrees Celsius 7.

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.

The final mass of each solution was recorded in the data table. Next, each solution was placed in individual cuvettes and its absorbance and percent of transmission at 630 nm were recorded by a spectrophotometer. The reason the machine was at 630 nm was that the blue absorbs red light and reflects blue light.

3.) Measure the mass of the first substance (0.25g) on the balance scale accurately. Once measured add the substance into the boiling tube containing 20ml of water and make sure the thermometer is still in the boiling

In this lab the concentration of allura red will be found. The vernier colorimeter will be used for this lab. Stock solution of a known concentration will be made, the absorption of each will be measured, when absorbance vs. concentration is plotted it should result in linear plot, which is called a calibration plot. The plot comes from the beer-lambert law, which is A=Kc. Measuring the concentration of allura red can be found by measuring the absorption of light through the solution. Cuvettes will be used in this lab to find concentration each solution; they will be placed in the cuvette then put into colorimeter to find absorption. Once that is complete data pairs will be examined by making a graph of absorbance vs. concentration with a

4. Prepare a vacuum filtration apparatus using a buchner funnel. Obtain one filter paper for each one of your samples, weigh them and record their mass in your notebook (label them with a pencil to be able to differentiate them later).

Of Exp #5: In this experiment we will learn about the spectroscope and how it works. To learn the concept of quantitative measurements, to construct a spectroscope and, to use it for taking quantitative measurements.