Bromination Of Arenes Lab Report

Good Essays
al Chain Reactions: Bromination of Arenes

Introduction The purpose of the bromination of arenes was to determine the different reactivities of different hydrocarbons with different hydrogen atoms when reacted with bromine under free-radical substitution. The time it took for the bromine color to disappear was used to determine the order of reactivity of the different hydrocarbons.

Data and Results The data of the 10 hydrocarbon tubes and the 2 control tubes with bromine and dichloromethane in the two different conditions is listed below in Table 1. As a result, the hydrocarbon tubes in light reacted and lost the bromine color quicker than the tubes not in light. Not all of the hydrocarbons observed a full disappearance in the bromine color, but did observe a color change. The control tube had
…show more content…
The more selective a radical is the least reactive is. Since the chlorine radical is more reactive than the bromine radical, the bromine is more selective than chlorine. Using Hammond’s Postulate, since bromine radicals are lower in energy, less reactive, and endothermic it has a late transition state. Therefore, the transition state resembles the products over the reactants, the energy difference is large, and the bromine radical is more selective. Since bromine is more selective, it is used in most experiments.

Conclusion The predicted reactivity of the five hydrocarbons in free-radical chain bromination in increasing order was ethylbenzene (9), toluene (8), methylcyclohexane (13), cyclohexane (12), and tert-butylbenzene (11). This hypothesis was a result of the fact that benzylic hydrogen atoms react faster than aliphatic hydrogen atoms and aliphatic hydrogen atoms react faster than aromatic hydrogen atom atoms. The hypothesis was in fact correct and the reaction times of each hydrocarbon with different hydrogen atoms in the bromination experiment support

You May Also Find These Documents Helpful

  • Powerful Essays

    Bromination Solo Experiment 3 – Individual Lab Report (Save as pdf and submit, due by 12:00 NOON one week after experiment) Last Name: First Name: TA Name: Date Lab Performed: Date Lab Submitted: Group A, B, or C: Comments for Grading TA: (Please indicate if you performed the lab on a day other than your regularly scheduled day and/or with a TA other than your regular TA). Page Limit: report must not exceed FIVE pages (including this page) LIMIT DOES NOT INCLUDE ANY GRAPHS, SPECTRA…

    • 1196 Words
    • 5 Pages
    Powerful Essays
  • Satisfactory Essays

    Radical Bromination demonstrates the process of halogenation – where a halogen replaces a hydrogen in a molecule. Mechanism starts by breaking the bromine bonds by heat/light, forming radical halogen (initiation). The bromine radical then breaks a C-H bond on the molecule, forming a benzylic radical, and that same radical then attacks Br2 to regenerate bromine radical. Termination will then occur when the concentration of Bromine runs low. NBS is also used in this experiment to keep the bromine concentration…

    • 106 Words
    • 1 Page
    Satisfactory Essays
  • Powerful Essays

    Arene Molybdenum Lab

    • 2459 Words
    • 7 Pages

    Arene Molybdenum lab Introduction: Organometallic chemistry is the study of chemical compounds that contain carbon atoms bound to a metal atom. Organometallic compounds can contain main group elements, or more metallic elements such as zinc or carbon. These compounds tend to have carbon atoms bound to the metal center by σ-bonds. Alternatively, transition metals can be involved in the compound, which leads to a variety of interesting and diverse chemical characteristics. For example, a promising…

    • 2459 Words
    • 7 Pages
    Powerful Essays
  • Satisfactory Essays

    Lab 3: Bromination of Acetanilide CHEM 2110 Hassan Alsaleh 0525970 Due date :11/02/2015 Q1: To find the limiting reagent we need to find the number of moles of acetanilide, and the number of moles of Bromine. Mass of Acetanilide used = 0.67g Molar mass of Acetanilide = 135.16g/mol[1] Number of moles of Acetanilide = (0.67g) / (135.16g/mol) = 0,005 mols Volume of Bromine = 0.25ml Density of Bromine = 3.103 g/ml[2] Mass of Bromine = (0.25ml) X (3.103g/ml) = 0.78g Molar mass of Bromine…

    • 368 Words
    • 2 Pages
    Satisfactory Essays
  • Good Essays

    Chemistry of Arenes

    • 1460 Words
    • 6 Pages

    Arenes The aromatic hydrocarbons also have the name arenes. They contain in their molecule one or more cycles made up from 6 carbon atoms. When the molecule is formed out of a single cycle, the hydrocarbons are mono nucleuses; when the molecule contains more than one cycle, the hydrocarbons are poly nucleuses. The simplest aromatic hydrocarbon, benzene, is compound out of just one such cycle; its formula is C6H6. The representation of benzene through a cycle of 6 carbon atoms with 3 double bounds…

    • 1460 Words
    • 6 Pages
    Good Essays
  • Powerful Essays

    Bromination of Acetanilide Objective: The objective of this experiment was to use melting point and NMR to determine which of two isomers, ortho or para, would most likely form after brominating Acetanilide through electrophilic aromatic substitution. Procedure/Observations: 1. Weigh out ~280 mg of acetanilide in a 10 mL r.b. flask with a stir bar. 2. Then, add 2.0 mL of glacial acetic acid using a calibrated Pasteur pipet. 3. Stir the mixture until all of the acetanilide has dissolved…

    • 547 Words
    • 3 Pages
    Powerful Essays
  • Satisfactory Essays

    Bromination of Acetanilide Introduction: Bromination of acetanilide to 4-bromoaniline was studied in this experiment. One of the most important mechanism with the reaction of aromatic compounds is the electrophilic aromatic substitution reactions(wade,2013). The electrophilic aromatic substitution enable scientists to make substituted aromatic compounds. However, substitution groups affect the electrophilic substitution mechanism. A nitrogen atom attached to hydrogen is learned to be a powerful…

    • 333 Words
    • 2 Pages
    Satisfactory Essays
  • Good Essays

    Greener Brominations

    • 971 Words
    • 4 Pages

    Greener Brominations Abstract In this experiment, trans-stilbene was brominated and debrominated with the use of three methods: bromination with pyridinium tribromide, bromination with hydrogen peroxide and hydrobromic acid, and debromination with zinc. The yields of parts A, B, and C are as follows: 68.6 %, 54.6 %, and 55.9 %. Introduction In the chemical process of bromination, an alkene is halogenated with bromine. Solvents that are typically used include methylene chloride and carbon…

    • 971 Words
    • 4 Pages
    Good Essays
  • Better Essays

    Bromination of Acetanilide

    • 1035 Words
    • 5 Pages

    BROMINATION OF ACETANILIDE OBJECTIVE Aim of the experiment was too brominate acetaldehyde to form p-bromoacetanilide. INTRODUCTION Acetanilide is a chemical compound with the chemical formula of C6H5NH(COCH3). It is a crystalline solid that is prepared by acetylation of analine and is widely used in the dye industry. This crystalline solid is an odourless solid chemical that has a flake or leaf like appearance. It is also known as N phenylacetamide, acetanil or acetanilide. Its former…

    • 1035 Words
    • 5 Pages
    Better Essays
  • Better Essays

    Alkene addition: Bromination of (E) Stilbene Introduction: In this lab we used the greener approach, which involves the addition of bromine across a double bond. When bromine reacts with E-stilbene (trans-1,2-diphenylethene), two new chiral carbons are created from the sp2 carbons, therefore 3 different dibrominated stereoisomers are possible: meso-(1R,2S), or the raceminc mixture-(1R,2R) or (1S,2S)-dibromo-1,2-diphenylethane (Gilbert, 2010). When the bromination ion intermediate proceeds…

    • 1023 Words
    • 5 Pages
    Better Essays