• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
Page
  1. 1
    1
  2. 2
    2
  3. 3
    3
  4. 4
    4
  5. 5
    5
  6. 6
    6
  7. 7
    7
  8. 8
    8
  9. 9
    9
  10. 10
    10
  11. 11
    11

Preparation of propanone from propan-2-ol

Extracts from this document...

Introduction

Date: 11/10/2011 Exp. No.: 23 Title: Preparation of propanone from propan-2-ol Aim: The aim of this experiment is to prepare propanone by oxidizing propan-2-ol with acidified potassium dichromate solution. Introduction: Ketones and aldehydes are important series in preparation of other compounds and they are commonly prepared by oxidizing alcohol which is done in this experiment. The experiment is an oxidation reaction where a secondary alcohol (propan-2-ol) is oxidized by acidified potassium dichromate. The reaction does not need to be heated but should be placed in an iced water bath as the reaction is highly exothermic. The product is propanone and no catalyst is needed for the reaction. The propanone is serparated from the reaction mixture by simple distillation and is purified using anhydrous cacium chloride. The equation of this reaction is as follow: Chromic acid is produced in situ by adding potassium dichromate (VI) with sulphuric acid and water. K2Cr2O7 + H2O + 2H2SO4 ? 2 H2CrO4 + 2 NaHSO4 The term chromic acid is usually used for a mixture made by adding concentrated sulfuric acid to a dichromate, which may contain a variety of compounds, including solid chromium trioxide. ...read more.

Middle

The equation is as below: Why do we need to use ice bath? This is because the boiling point of propanone is only 56oC, during the oxidation, the boiling point of propanone would be reached as the oxidation was very exothermic. If the iced water bath was not used, most of the propanone would be vaporized and escape from the reaction mixture. This causes loss of the product. Therefore, we need to use an ice bath during the oxidation to minimize the amount of propanone vaporized. Why do we need to use anhydrous sodium chloride? This is because even after distillation, the product might contain some water. We need to use anhydrous sodium chloride as a drying agent to extract the water molecule mixed in the organic product. Why does the ketone further oxidize to form carboxylic acid? Ketone may undergo further oxidation to form carboxylic acid with acidified potassium permanganate and under reflux. This reaction has very high activation energy because this requires breaking the strong C-C bond Why do we use the suction flask instead of purely using the gravitational force to filter the crystals? This is because if we do not use the suction flask or any negative pressure, the filtration process will be too slow. ...read more.

Conclusion

Geminal halide hydrolysis The reactants are a geminal dihalide and water or a hydroxide. The reaction product is a ketone or an aldehyde. The first part of the reaction mechanism consists of an ordinary nucleophilic aliphatic substitution to produce a gem-halohydrin. Ruzicka Large Ring Synthesis Formation of large ring alicyclic ketones from dicarboxylic acids by thermal decomposition of salts with metals of the second and fourth groups of the periodic table (Ca, Th, Ce) Nef reaction Carbonyl compounds can also be formed using the Nef reaction. The Nef reaction is an organic reaction describing the acid hydrolysis of a salt of a primary or secondary nitroalkane (1) to an aldehyde or a ketone (3) and nitrous oxide (4). Precaution of this experiment 1. Concentrated sulphuric acid is highly corrosive and oxidizing, so it must be handled with care. 2. Acidified potassium dichromate is also very oxidizing, so it should also be treated carefully. 3. If any concentrated sulphuric acid or acidified potassium dichromate are in contact with our skin, we should wash it with running tap water immediately. 4. During the oxidation of propan-2-ol, safety goggles should be worn as this reaction is highly exothermic. Reference: http://en.wikipedia.org/wiki/Chromic_acid http://www.chemguide.co.uk/organicprops/alcohols/oxidation.html http://www.docbrown.info/page07/redox3.htm http://chemistry.boisestate.edu/people/richardbanks/organic/nomenclature/ethernomenclature1.htm http://www.angelfire.com/bc2/OrgChem/ethers.html http://www.chemicalforums.com/index.php?topic=32190.0 http://www.newworldencyclopedia.org/entry/Ketone http://www.lookchem.com/Chempedia/Basic-Chemical/Chemical-Reaction/8524.html http://www.wellesley.edu/Chemistry/chem211lab/Orgo_Lab_Manual/Appendix/ClassificationTests/aldehyde_ketone.html http://scmwaterproofporous.blogspot.com/2010/10/buchner-funnel.html ?? ?? ?? ?? ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Organic Chemistry section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Here's what a teacher thought of this essay

5 star(s)

This is a highly detailed, well laid out experiment with excellent alternative methods.
This piece of work is 5*

Marked by teacher Brady Smith 20/02/2012

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Organic Chemistry essays

  1. Peer reviewed

    The Synthesis Of Phenacetin From p-Acetamidophenol

    5 star(s)

    The crude product then was filtered and washed with a little cold water and stored in a desiccator until the following week for recrystallisation. The following week the product was recrystallised from aqueous spirit (1:1 volume) and dried in the vacuum oven at 40oC.

  2. Thermal Decomposition of Copper Carbonate

    The mole ratio between oxygen and copper carbonate is : 2 and this is a quarter of the number of moles of copper carbonate. Therefore 0.0004048 moles of oxygen will be present in the reaction. The volume of a given number of moles of gas (CO2 + O2)

  1. Free essay

    Experiment to determine the order of the reaction of Iodine with Acetone by using ...

    Therefore, rate of change of the iodine concentration is independent of iodine concentration. The reaction of iodine with acetone is zero order with respect to I2. Graph2 ( please refer to the graph paper attached) By combining the results of Group 1, 2 and 3 class results are obtained.

  2. The aim of this investigation is to analyse mummion, which is an inorganic solid ...

    X1 To remove crystals from the mummion solution Goggles and lab coat X1 To protect your eyes and body Method: 1.

  1. Comparing the rates of hydrolysis of chloro-, bromo- and iodo- alkane

    The reactivity of halo group on the rate of the hydrolysis reaction is: iodo- > bromo- > chloro- The reactivity depend on the bond strength of the C-- X bond, the weaker the strength of the C-- X bond, the more reactive the solution is.

  2. The preparation of cyclohexene from cyclohexanol

    After that a stir bar was dropped in the flask too. 5. The flask was fit with the factional column. 6. Finally, the flask was completely immersed into the oil bath, which was placed on the hot plate. C.

  1. Comparison between Cyclohexane and Cyclohexene

    Cyclohexane contains only single bond, so it does not react with bromine readily. In part C where cyclohexene is added to bromine water, immiscible layers are formed at the end of the reaction. Both excess cyclohexene and the product form from the reaction do not mix readily with water.

  2. Extraction of alcohol from beer by distillation.

    The alcohol in the round bottom flask in the bucket was collected and measured into a measuring cylinder, and results were recorded. TESTING FOR ALCOHOL 1. The measuring cylinder containing the pure alcohol was taken over to the fume cupboard.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work