Preview

Crystal Violet Formal Lab

Powerful Essays
Open Document
Open Document
2472 Words
Grammar
Grammar
Plagiarism
Plagiarism
Writing
Writing
Score
Score
Crystal Violet Formal Lab
Determination of Reaction Rate Law from the Reaction of Crystal Violet with Sodium Hydroxide
______________________________________________
Abstract: This experiment helps determine the rate of reaction of crystal violet while it reacts with sodium hydroxide with respect to crystal violet. The amount of sodium hydroxide is varied in this experiment while crystal violet is kept at a constant. The transmittance of crystal violet is observed and recorded using a colorimeter and the data obtained is used to plot graphs which are manipulated using LoggerPro software to produce the desired outcome; rate of reaction of crystal violet. Upon completion of the experiment it was seen that the rate of reaction of crystal violet turned out to be 1 which meant the reaction was first order with respect to crystal violet. This was deduced upon plotting the graph of ln Absorbance versus time of crystal violet and by drawing the line of best fit, which showed that the slope graph was 1 which is the rate of reaction. This whole experiment was based upon the equation: Rate= k [CV+] [OH-], where k stands for the rate constant.
Introduction: Kinetics, which is the study of how fast a reaction takes place or in other words the rate of a reaction, is the main ideology in this experiment. Reaction rates can be measured in a number of ways: by monitoring the amount of product formed, by measuring the loss in mass of reactants, for reactions involving gaseous products measuring the volume of gas produced, by electrolytic conductivity, pH measurement or for colored reactants or products measuring the transmittance by the use of a colorimeter. In this experiment the last method of measurement is used which is colorimetry.
Colorimetry is a method of determining the kinetics of a reaction using a spectrometer which observes the amount of light that is absorbed or transmitted through a colored solution. As a reaction proceeds, the reactants either fades away or the product forms



References: 1. Atkins, P. W. (1978). Physical chemistry. San Francisco: W.H. Freeman. 2. Allen, J. P. (2008). Biophysical chemistry. Malden, MA: Blackwell Pub. 3. Lindon, J. C., Tranter, G. E., & Holmes, J. L. (2000). Encyclopedia of spectroscopy and spectrometry. San Diego: Academic Press. Appendix: Solution 1: Order 0, ǀRMSE/aǀ= 0.01641/0.271= 0.0605 Order 1, ǀRMSE/aǀ= 0.01129/0.271= 0.0416 Order 2, ǀRMSE/aǀ=0.3810/0.217= 1.4050 Solution 2, Order 1, ǀRMSE/aǀ=0.01566/0.134= 0.1169 Solution 3, Order 1, ǀRMSE/aǀ= 0.00693/0.492= 0.0141

You May Also Find These Documents Helpful

  • Good Essays

    CHEM 1252 Lab Report 5

    • 1825 Words
    • 21 Pages

    The purpose of this experiment was to determine the differential rate law for a chemical reaction based on the relationship between the concentration of reactants and the rate of reaction. Since spectrophotometers, like Spec-20s, provide information about concentration, these instruments were used to monitor the increase or decrease in concentration of a reactant in a solution over time. By plotting [phph2-] versus time and changing the concentration of OH- used, the order of the reaction with respect to each reactant and the overall order of the reaction can be determined.…

    • 1825 Words
    • 21 Pages
    Good Essays
  • Satisfactory Essays

    Chemistry 116 lab review

    • 289 Words
    • 2 Pages

    The first step is to calibrate the colorimeter with0.20 M Fe(NO3)3and set the absorbance at 470 nm since it is known to keep an acidic solution throughout the entirety of the experiment. It was important to do this right at the beginning of the lab since the zeroed value of the acid was the calibration number for all of the other solutions. A total of seven solutions with different dilutions were used throughout the lab to conduct the equilibrium constant. The first step was adding 5 mL of 0.200 M Fe(NO3)3to each of the 5 test tubes. Once this was done, 0.00200 M NCS was added to the test tubes, each receiving a different amount; test tube one received 1 mL NCS-and with each test tube the amount of NCS-would increase by 1 mL, test tube 5 received 5 mL of NCS. . The next step was adding HNO3 to each test tube in different volumes; Test tube one received 10 mL of HNO3 and with each test tube the amount of HNO3 decreased by 1 mL, test tube five had no HNO3 added to it. The addition of these solutions formed five test tubes of different dilutions, but of equal volume, 10 mL each. After all of the previous trials had been completed the final step was to take each test tube and pour it into a different cuvette and measure the absorbance for each. Once the initial concentration was calculated of Fe3+, NCS and FeNCS2+ in molarity. The absorbency values were recorded and used to calculate the formation constant, K f The reference table containing volumes used in each solution is provided below…

    • 289 Words
    • 2 Pages
    Satisfactory Essays
  • Satisfactory Essays

    AP Chemistry Kinetics Lab

    • 335 Words
    • 2 Pages

    The purpose of this lab is to learn how to write law expressions, determine orders by graphs, and calculate rate constants. By determining the number of drops of sodium hypochlorite necessary to make a diluted food dye change to colorless in less than three minutes helps calculate the absorbance which can then be analyzed to find the pseudo rate constant and eventually leading to the rate constant and the rate law. The results show that the m and n are both 1st order which makes the overall order of the blue dye 2nd order.…

    • 335 Words
    • 2 Pages
    Satisfactory Essays
  • Powerful Essays

    W - Kinetics of the Reaction of a Food Colourant with Sodium Hypochlorite ..................... 31…

    • 7286 Words
    • 43 Pages
    Powerful Essays
  • Good Essays

    Experiment: First all the materials were gathered. Pigments were separated by chromatography paper. Pigments were loaded in a line on the paper. The paper was folded in a cylinder, stapled, placed in a cylinder with solvent, and sealed with wax paper until the pigments separated. After the pigments separated the paper was taken out to dry and the separated pigments were cut out. Four groups joined together to perform the remainder of the investigation. All of the groups' pigments were separated and put into separate test tubes. Acetone was added. Using forceps, the strips of chromatography paper were "washed" of their pigment. Lastly the absorption spectrum, the absorption pattern for a particular pigment, was measured.…

    • 420 Words
    • 2 Pages
    Good Essays
  • Good Essays

    Chm 116 Lab

    • 830 Words
    • 4 Pages

    Chemical kinetics, which can also be explained as reaction kinetics, studies the rates of chemical processes and reactions. A lot of this has to do with the speed at which a chemical reaction occurs for instance the rate at which reactants and products appear and disappear. In this case chemical kinetics goes further in depth to understand what conditions affect the rate of a given reaction. This is important because it allows scientists to determine what type of reaction can occur, and how they can alter the outcome under varying conditions. Gasoline and diesel for example have two very different reaction rates when exposed to a spike in temperature. If you were to light gas on fire it would instantaneously explode igniting fumes in the air as well, however diesel has a much higher ignition temperature allowing it to slowly burn if lit. These two types of fuel are an example of the differences in reaction rate. To determine the rate at which these reactions occur we use the rate law: r=kAxBy. In this equation we are looking to solve for the rate of the reaction “r”, the k value which represents our rate constant is simply the value which quantifies the speed. As for the [A] and [B] values they are the concentration of the species A and B which respectively are raised to the “x” and “y” power. The “x” and “y” values are the respective stoichiometric coefficients that must be determined experimentally. The primary goal essentially for this experiment is to determine the k value or rate constant along with the x and y stoichiometric coefficients given the concentrations of Crystal Violet and Hydroxide. This can be obtained using a spectrophotometer to determine rate of absorbance then graph the rate find a line of best fit, determine our rate constant, then finally solve for our x and y in the rate law equation. Beer’s law also known as Beer-Lambert law relates the absorption of light to the properties of the material through which the…

    • 830 Words
    • 4 Pages
    Good Essays
  • Good Essays

    Colorimetric Analysis

    • 421 Words
    • 2 Pages

    2. If this analysis was performed using a colorimeter, yellow light would be used to measure the absorbance of solutions. Why is blue light not used?…

    • 421 Words
    • 2 Pages
    Good Essays
  • Good Essays

    Lab 1

    • 784 Words
    • 4 Pages

    Introduction: The intent of the experiment is to sucessfully understand that chemistry is an experimental science which is dependent upon certain observation and the use of good laboratory techniques. The experimenter should become familiar with basic operations necessary throughout this course. The objective of this experiment is to acquire the use of common and simple laboratory equipment.…

    • 784 Words
    • 4 Pages
    Good Essays
  • Powerful Essays

    Reactants Lab

    • 1408 Words
    • 6 Pages

    This experiment was done to determine the effects of the nature of the reactants, concentration, temperature, surface area and catalyst on the rate of chemical reactions. The nature of the reactants implies a difference if the reactants are aqueous or organic, acidic or basic or if they occur in the same phase or not. Acid-base reactions, formation of salts, and exchange of ions are fast reactions while reactions in which large molecules are formed or broken apart are usually slow. Generally, the rate of reaction is directly proportional to the concentration of the reactants, as well as to the temperature. Greater surface areas and addition of catalysts also increase the rate of chemical reactions.…

    • 1408 Words
    • 6 Pages
    Powerful Essays
  • Good Essays

    Bleaching of Allura Red

    • 1211 Words
    • 5 Pages

    Katie Berry TA: Jason Fahrion April 10, 2013 A Kinetic Study of the Bleaching of Allura Red Introduction: In this laboratory experiment, we studied the kinetics of the reaction between Allura Red (C18H14N2O8S2) and bleach. C18H14N2O8S2 (aq) + NaOCl (aq) → products Allura Red is a food dye, which is an organic molecule with alternating single and double bonds. The color of the dye comes from the delocalization of electrons in the π­bonding system (Exton, 149). Bleach is an aqueous solution that contains sodium hypochlorite (NaOCl). The hypochlorite of bleach breaks the double bonds of the food dye through oxidation, forming molecules that do not absorb visible light and thus bleaching the product. During this process, hypochlorite is reduced to chloride and hydroxide ions. OCl­ (aq) + H2O (l) + 2e­ → Cl­ (aq) + 2OH­ (aq) Our goal in this experiment was to observe the reaction and concentration changes between Allura Red and bleach and determine the rate law for the reaction. The rate of reaction can be found by the equation rate = ∆concentration / ∆time = k[Allura Red]x[NaOCl]y The x and y values indicate the order with respect to each reactant, and k represents the rate constant for the reaction. These values had to be determined experimentally. In order to determine the rate law of the reaction, we had to use spectrophotometry in order to monitor the change in absorption of the various reactions. Since Allura Red was the only colored species in the reaction, we were able to monitor the rate by observing the decrease in color of the solution with time. From the absorption values, we were able to calculate the concentrations from Beer’s law: A=ϵBC (1). Five different trials were performed with various concentrations of Allura Red, bleach, and water. The equation: M1V1 = M2V2 (2) was used in order to calculate the initial concentrations of Allura Red and NaOCl for these trials. Graphs of concentration of Allura Red ([AR]), ln[AR], and 1/[AR], as a function of time…

    • 1211 Words
    • 5 Pages
    Good Essays
  • Powerful Essays

    The purpose of this project is to identify an unknown organic acid (X) by conducting various experiments to determine the acid’s unique properties. By determining selected constant properties of the unknown and then comparing these properties to the constant properties of known substances, it is possible to identify an unknown substance. The properties used to identify the unknown must be intensive, or independent of amount. Both chemical properties and physical properties are intensive properties used in determining the identity of an unknown (Maserton, p. 15).…

    • 1577 Words
    • 7 Pages
    Powerful Essays
  • Best Essays

    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 substance and is reflected back and read by galvanometer which had the ability to detect electric currents (Verma, R). The absorbance reading is then given, absorbance is usually between 0.0 – 2.0, any higher than 2.0 may mean not enough light is getting through to the galvanometer (Bhowmik and Bose, 2011). When using the spectrophotometer it is necessary to use a control or blank to zero or tare the machine in between every new wavelength or concentration, this control is water (Ayyagari and Nigam, 2007). The correlation between the numbers acquired through spectroscopy can be seen using the Beer- Lambert Law. The Beer- Lambert law states that the amount of light absorbed at a certain wavelength is proportional to the concentration of the absorbing substance (Fankhauser, 2007).…

    • 2210 Words
    • 9 Pages
    Best Essays
  • Powerful Essays

    11. Reusch, William H. “Infrared Spectroscopy.” Michigan State University Department of Chemistry. Web. 2011. <http://www2.chemistry.msu.edu/faculty/reusch/VirtTxtJml/Spectrpy/InfraRed/infrared.htm>.…

    • 4316 Words
    • 18 Pages
    Powerful Essays
  • Good Essays

    References: [1] A. M. Cassell, J. A. Raymakers, J. Kong, H. Dai, J. Phys. Chem. B, Vol. 103, No. 31, pp. 6484-6492, 1999.…

    • 831 Words
    • 4 Pages
    Good Essays
  • Powerful Essays

    The objectives of this experiment are to understand why and how spectroscopy is used to determine the components and concentrations of a solution, describe various types of spectroscopy, describe the visible and ultraviolet regions of the electromagnetic spectrum, define Beer’s law and define the relationship between absorbance and transmittance. Other learning objectives are to create a Beer’s law plot for a series of samples with known concentrations, collect spectrophotomic data from unknown and known FDC blue dye samples, perform serial dilutions, calculate concentrations, perform linear regression and determine the equation of a best fit line.…

    • 1297 Words
    • 8 Pages
    Powerful Essays