Crystal Violet Kinetics Lab

Make sure to use the same type of cuvette to keep the width consistent and to prevent any experimental error from arising. Obtain 5 of the same type of cuvettes and pre-rinse them thoroughly. Label them numbers one through five in increasing molarity. Then, fill each of the cuvettes with one of the five solutions you created back in Part A. We will first examine the solution that exhibits the highest concentration or molarity. Make sure to wipe the outside of the cuvette with a Kimwipe before placing into the SpectroVis Plus device. Observe the graph that is generated and make sure to take note where the maximum absorbance takes place.

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

Introduction: The goal or purpose of this experiment was to determine the concentration of Allura Red in red commercially available beverage- Gatorade. Colorimeter are used to shine a LED light through the solution and hit a photocell: it will detect an absorbance or a percent transmittance value. These “value” can be charted and examined as a calibration curve. Calibration curve is a method for determining a substance concentration in an unknown sample

The higher concentration of a solution, the more light is absorbed. The slope of the calibration curve is y=543949x-1.4302, y being the percent absorbance and x being the phosphate content, this is shown in Figure

With these absorbance numbers a concentration curve was constructed and the unknown solution was determined by finding the point of absorbance on the curve.

Purpose: The purpose of this experiment is to use kinetics to study a solvolyis reaction

Introduction: Chemical reactions are dependent upon two factors: temperature and concentrations of substance. We can monitor the rate at which a chemical decomposes or the rate at which a chemical substance appears. In this experiment we will be measuring the rate of decomposition of hydrogen dioxide with the following reaction:

It was found out that our graphs for yellow 5 and yellow 6 were half the concentrations needed to mimic orang PowerAde. This was found out with the help of the TA. Both the Full Throttle and orange PowerAde used twice as much food dye concentration then what was provided for the experiment. In order to compare our made solution with the beverage, orange PowerAde needs to be diluted to a solution that contained 50% distilled water and 50% PowerAe To do this, take 5 mL of orange PowerAde and add 5 mL of distilled water. A new absorption graph can be formed and used to compare with the made

In this experiment, two reactions were run to determine the molar absorptivity and the equilibrium constant of FeSCN2+. The main principles used in this lab are equilibrium, LeChatlier’s Principle, Beer’s Law and Spectrocopy. The first reaction was run to completion using LeChatier’s Principle and the second reaction was run to equilibrium. A spectrophotometer was used to measure absorbances. Using a graph of absorbance versus concentration of FeSCN2+ was used to determine that the molar absorptivity constant was 3670. Beer’s Law was used to determine that the average equilibrium constant was 33.1793.

Beer’s Law is a direct liner relationship between the absorbance of light are a selected wavelength and the concentration the absorbing species in the solution. (Sullivan 241). Beer’s Law shows a relationship between several concentrations. To determine if the determine our data consistent with Beer’s law, we will plot a graph of absorbance versus concentration with a linear regression

The absorbance is measured using a Plate reader and a Standard curve is generated. Also, the different types of pipetting techniques are assessed in this Assay.

We set the wavelength of the spectrophotometer to 447 nm so we could achieve maximum sensitivity. At this point, the change in absorbance per unit of concentration is greatest and there is greater adherence to Beer’s Law.

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

To make a dilution use M1 x V1 = M2 x V2 to calculate the volume of of .2500M in mL needed to make 25.00L of a .05000M diluted solution. Add DI water to the diluted solution and invert the flask to ensure complete mixing. The solution from scratch and the dilution will then be used to identify an unknown concentration solution. Six dilute solutions will be prepared using varied quantities of concentrate to construct an abosrbance vs. concetration calibration graph. After measuring the absorbance of each of the six known solutions , the best wavelength is to be determined. Then measure the absorbance of the solution prepared from scratch, dilution and unknown. Using the equation associated with our graph we are to determine the molarity of the solution prepared from scratch,dilution and unknown. With the solution made from scratch and the dilution the percentage errors were rather low at 2.5% . According to the graph the calculated concentrations were .049M , slightly under the .050M desired concentration making the calculated concentrations moderately

The ending result of this experiment confirms that as five test tubes are lined up with the varying level of absorbance, different results in the level of absorbance will appear as well, this is visible in above table. Thus, this is due to the varying amount of water in the solution. The blank sample had a 0.30 in its level of absorbance.