Spectroscopy Lab Report

The concentrations and absorbances of the red and blue dyes were used to find the concentration of the purple dyes. From the graph of the blue dye, the linear equation for absorbance was y = mx + b. From that formula came the equation y = 7.915 x 104 (x) + 0.02489, where y represents absorbance, m is slope, x is concentration/molarity, and b is the constant/y-intercept. The same set up was performed for the red dye, but the equation produced was y = 1.045 x 104 (x) +.001298. The equations found when graphing absorbance vs. concentration were used to find the concentration of the purple dyes. The absorbance for purple dye 3 on the red wavelength of 470 nm equaled 0.149 and 0.818 for the blue wavelength of 635 nm. For purple dye 1

Spectroscopy is the study of light. A spectrophotometer is a machine used to determine the absorbance of light at any given wavelength. It does this by using a source of white light through a prism, which gives multiple wavelengths that can be individually focused (Ayyagari and Nigam, 2007). Substances are put into cuvettes that are glass or quartz containers that light can easily travel through. The light that is being focused travels through the substance gets absorbed by the

A spectrophotometer’s purpose is to use colors of the light spectrum to determine the concentration of light absorbing molecules in a solution. (p.59) In this particular lab, our mission was to determine the protein concentration and the standard curve of the unknown sample of BSA. This, by preparing five dilutions of the unknown solution of BSA together with other known concentrations, and then experimenting by observing how the concentrations were passed through the spectrophotometer. The outcome resolved in the absorption levels being decreased, and this

For this experiment, the amounts of Red 40 and Blue 1 were quantified in six different Kool-Aid samples through the use of a spectrophotometer. This was completing by performing serial dilutions on both dyes, Red 40 and Blue 1, and then creating calibration curves for each of the six samples. The absorbance and maximum wavelength values were obtained from the spectrophotometer for each individual drink sample. Beer’s Law was used to discover the concentration of

Each stock solution was placed in a colorimeter and was tested for it Absorbance. A computer program tested and drew up the Calibration curve/linear fit equation. However, the computer could not protect potential errors. An error for determining the concentration of the diluted and undiluted, could be a skew linear fit equation. The linear fit equation could be skewed by having an inadequate ratio of the stock solution and distilled water. For example, when making stock solution 1, 0.021(L) was used instead of 0.020(L) can throw the calibration curve, resulting a skewed linear fit equation. If the “blank” was not fully clean or had left over Allura Red residue, then the “blank” was tampered with. A tampered “blank” means any comparisons with it would have a wrong Absorbance reading. However, the most likely and most effective error, is calculation. Using the wrong V1 and V2 to determine the concentration of the undiluted would affect the answer of the grams Allura Red would be consume and the amount of molecules of Allura Red. The colorimeter is adjusted to a wavelength of 470 nm is maximize the absorbance of the Allura Red. If wavelength was place at 565 nm, then Allura Red would not absorb as much color of

Station one: Station one shows that when a small piece of magnesium metal is placed over the flame of the Bunsen burner, the magnesium metal ignites, giving off a bright, white light. Once the flame has extinguished itself due to the lack of fuel, the magnesium metal turned from a metallic strip to a crumbled white powder. It can be decided that station one is a combination (redox) reaction, as a new product is synthesised by the combination of two reactants. The reactants, magnesium and oxygen gas in the air bonded together to form the product of magnesium oxide.

The dyes in the laboratory experiment are made of numerous colors, mainly red and blue, the spectra from each of the dyes corresponded to the wavelengths obtained from each of dye i.e. 620 nm for red and 450 nm for blue.

Beakers 5-8 were set aside for later use. I then recorded by observation of beaker 1 in Table 1 on the Lab Reporting Form; this included smell, color, etc. 10 mL of vegetable oil was added to beaker 2, 10 mL of vinegar to beaker 3, and 10 mL of liquid laundry detergent to beaker 4. Each beaker was mixed thoroughly with a wooden stir stick. My observations such as color and smell were annotated in Table 1 on the Lab Reporting Form. Next, I cut the cheesecloth into five different pieces. I took one piece of cheesecloth and folded it so it was 4 layers thick. I then placed it into the funnel. 60 mL of soil was measured out using the 100 mL beaker and placed into the cheesecloth lined funnel. The funnel was then put inside beaker 5. The contents of beaker 1 (water) were poured through the funnel and let filter for 1 minute into beaker 5. My observations were recorded on Table 1 on the Lab Reporting Form. I repeated the process of creating a filter of cheesecloth and soil and filtered the contents of beaker 2 (vegetable oil) into beaker 6, beaker 3 (vinegar) to beaker 7, and beaker 4 (detergent) to beaker 8. All observations were recorded on Table 1.

This is done through a change in temperature. Over time, two objects that are in direct contact will

This experiment was design to find the amount of copper in a penny using a visible spectroscopy. We achieved this by combining .89 to .93 of Cu(NO3)2*2.5H2O to a 25mL volumetric flask and filling the flask to about half full with deionized water, swirl, then fill to the line with more deionized water. After, fill a 25mL burret with Cu2+ stock, with this add .5, 1, 1.5, and 2 mL of the stock to four different volumetric flask, add 2mL of 15 M NH3 from the burret to each flask and swirl, then fill to the line with deionized water. First, calibrate the spectrophotometer then; enter samples of each of the four samples in the spectrophotometer to test the absorbency. For the penny stock solution, use a 500 mL filter flask with about 250 mL of 1 M NaOH, place a rubber stopper to the top and connect a inverted long stem funnel to it using tygon tubing, and place a 125 mL flask below it. Turn on the water aspirator, place the penny in the 125 mL flask, measure out 20-25 mL of 8 M nitric acid in a 50 mL graduated cylinder, and then slowly add it. It should take about 5-10 minutes for the penny to dissolve.

2. When 2.00 g of NaOH were dissolved in 49.0 g water in a calorimeter at 24.0 ˚C, the temperature of the

The mean voltage of the battery terminals while connected to the identification resistors is presented in Figure ‎4 12. These samples have been pulled out from the voltage sensor of the PEB panel. The voltage decreased as expected from 12.53 to 12.5 during first 20 seconds of connection to the

October 17, 18, and 19, samples were collected from multiple sites along the BSR. The class was split into groups, and samples were collected from seven separate locations along the river and WWTP. There was also a sample collected by the S which is located between sites four and five. For each of these sites, there were ten groups from other labs that also collected a sample from the BSR. At site two of the river, the location included multiple sources of possible contamination. A drainage site was located 200 yards upstream, along with a small PVC drainage pipe next to the collection site. Not only was there drainage running into the river, the site was under a bridge, and contained other trash scattered throughout the area. The

3. The spectrophotometer was set at 420nm. Distilled water was also used as the ‘blank’.

concentration, record the absorbance readings at a fixed wavelength, and plot the absorbance vs. concentration data. The wavelength of 520 nm was selected for experiment Part