Alcohol ppt slides


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Alcohol ppt slides

  1. 1. Alcohol<br />
  2. 2. Let’s Recall<br />
  3. 3. Let’s Recall<br />
  4. 4. Lesson objectives<br />
  5. 5. What areAlcohols?<br /><ul><li>Belong to a homologous series of organic compounds similar to alkanesand alkenes.
  6. 6. The hydrocarbon chains contain the functional group -OH (hydroxyl group)</li></ul>Structural Formula Chemical Formula<br />C2H5OH (molecular formula) <br />or<br />CH3CH2OH<br /> (condensed structural formula)<br />=<br />OH<br />
  7. 7. Naming the Alcohol<br />OH<br />OH<br />OH<br /><ul><li>Methanol
  8. 8. Total of one carbon atom (meth-)
  9. 9. CH3OH
  10. 10. Ethanol
  11. 11. Total of two carbons atoms (eth-)
  12. 12. CH3CH2OH
  13. 13. Propanol
  14. 14. Total of three carbon atoms (propan-)
  15. 15. C2H5CH2OH</li></ul>*Take note of the functional group’s location, highlighted by the dotted box<br />
  16. 16. H H<br />H C C H<br />H H<br />H O <br />H C C O H<br />H<br />Naming Alcohol<br /><ul><li>Replace the ‘e’ with ‘anol’ at the end of the name of the hydrocarbon </li></ul>Example:<br />H<br /> I<br />I<br /> H<br />ethan<br />anol<br />ethane<br />
  17. 17. Naming the Alcohol<br />OH<br />OH<br />OH<br />OH<br />OH<br />
  18. 18. Naming the Alcohol<br /><ul><li>The names of alcohol end withanol.
  19. 19. Alcohol are a homologous series with the general formula CnHn+1OH, where n is the number of carbon atoms in a molecule.
  20. 20. The simplest alcohol is methanol, with one carbon atom.</li></li></ul><li>Physical Properties of ALcohols<br />
  21. 21. Physical Properties ofAlcohols<br /><ul><li>Alcohols are soluble in water
  22. 22. but their solubility decreases as their molecular size increases.
  23. 23. Unlike the alkanes and alkenes, the first four alcohols are liquid at room temperature and pressure.
  24. 24. Although alcohols contain the –OH group, they are not alkalis. In fact, they are all neutral.</li></li></ul><li>Chemical Properties of Alcohols<br /><ul><li>Alcohols can take part in these reactions: Combustion and Oxidation</li></li></ul><li>Combustion<br /><ul><li>An alcohol burns in air to produce </li></ul>carbon dioxide and water vapour. <br /> ethanol + oxygen -> carbon dioxide + water vapour C2H5OH + 3O2-> 2CO2 + 3H2O<br />C2H5OH + 3O2 -> 2CO2 + 3H2O<br />
  25. 25. <ul><li>Flame produced is clean
  26. 26. Combustion of alcohols are useful because:</li></ul>1. Methanol is less likely than conventional fuel to explode in an accident. It is a clean fuel.<br />2. When alcohol beverage is burnt with food, it gives a distinct flavour.<br />Combustion<br />
  27. 27. <ul><li>We can oxidise an alcohol (for example, ethanol) by warming it with acidified potassium dichromate(VI).
  28. 28. Experimental setup:</li></ul>Oxidation<br />(ethanol)<br />C2H5OH + acidified K2Cr2O7<br />coldwater<br />CH3COOH<br />(ethanoic acid)<br />heat<br />
  29. 29. <ul><li>Chemical equation:</li></ul>Oxidation<br />+ 2 [O]<br />+ H2O<br />Ethanol<br />Ethanoic acid<br />
  30. 30. <ul><li>The colour of potassium dichromate(VI) changes from orange to green.
  31. 31. Oxidation of alcohol is used in: </li></ul>Breathalyzerto test the amount of alcohol consumed by drivers.<br />Oxidation<br />
  32. 32. Formation of ethanol<br /><ul><li> Ethanol can be manufactured from:</li></ul>1. hydration of ethene<br />2. fermentation of carbohydrates<br />
  33. 33. Formation of ethanol- Hydration of ethene<br /><ul><li>Ethanol is manufactured by the catalytic addition of steam to ethene. </li></ul>Conditions: <br />phosphoric(V) acid at 300 °C and 60 atm.Phosphoric(V) acid (H3PO4) acts as a catalyst.<br />CH2 = CH2(g) + H2O(g) ->CH3CH2OH (g)<br />
  34. 34. Formation of ethanol-Fermentation of carbohydrates<br /><ul><li>Fermentation is a chemical process in which microorganisms such as yeast act on carbohydrates to produce ethanol and carbon dioxide.</li></li></ul><li>Formation of ethanol-Fermentation of carbohydrates<br /><ul><li> Instructions:
  35. 35. In your own groups of four, set up an experiment according to the experimental set up (A, B, C or D) which you can find on the last pageof your worksheet.
  36. 36. Each group will only be allocated to one of the four set ups. </li></li></ul><li>Formation of ethanol-Fermentation of carbohydrates<br /><ul><li> Instructions:
  37. 37. Record your observations under the observations column after one week and upload your observations onto the class blog according to your allocated set up.
  38. 38. Your group is suppose to complete a series of questions pertaining to the experiment and hand in one set of answers per group two weeks later. </li></ul>(You can find the questions on the class blog). <br />
  39. 39. Uses of Ethanol?<br />solvents for paints, varnishes, perfumes<br />alcoholic drinks<br />oxidation<br />ethanol<br />fuel for vehicles<br />making ethanoic acid for preserving food and making esters<br />
  40. 40. Concept map construction<br /><ul><li>In your groups of four
  41. 41. construct a concept map on the concepts that you have learnt today
  42. 42. present your concept maps at the end of 5 minutes. </li></ul>(Use the space in your worksheet to construct your concept map and make sure that it would be visible on the visualiser).<br />
  43. 43. How it all ties up <br />