Lesson 9: Organic Reactions

• Elimination

  1. Similar to decomposition

  2. 1 reactant forming 2 products

  3. Alkane with 2 elements, taking away 2 elements gives space

  4. The carbons double bond with each other
• Condensation

  1. One type is esterification

  2. Forms an ester group when a carboxylic acid and an alcohol bond

  3. Hydroxyl from carboxylic acid and hydrogen from alcohol combine and form an ester group, leaving a water molecule

  4. Carboxylic acid and amine monomers make proteins and form an amide group with water as a byproduct
• Important: Oxidation → form more bonds to oxygen or less bonds to hydrogen; Reduction → form more bonds to hydrogen or less bonds to oxygen
• Hydrolysis

  1. Adding a water molecule breaks bonds and creates substances

  2. Adding water to an amide will give carboxylic acid and an amine
• Redox

  1. Oxidation means becoming more positive, loss of electrons

  2. Oxidizing an alkane will get an alcohol

  3. Form more bonds with oxygen and less with hydrogen in oxidation

  4. Reduction is reducing bonds of oxygen and more bonds with hydrogen by gaining electrons, they no longer need to share
• Combustion

  1. The burning of fossil fuels in the presence of oxygen

  2. Complete means there is enough O2 for the reaction

  3. Incomplete means there is not enough O2, leaving CO as a product
• Summary

  • Alkene + H-H → alkane
  • Alkene + H-OH → alcohol
  • Alkene + H-X → alkyl halide
  • Alkene + X-X → alkyl halide (di-)
• Oxidation/Reduction (Redox)

  1. Electrons are being exchanged in compounds

  2. Something being reduced and oxidized

  3. Reduction is the gain of electrons (more negative)

  4. Oxidation is loss of electrons

  5. If a molecule is being reduced, the other molecule involved has to be oxidized to conserve matter
• Markovnikov’s Rule: The halogen or hydroxyl group will always bond to the more substituted carbon (i.e. the carbon that is bonded to more carbons)
• Addition

  1. 2 reactants forming a product

  2. Adding elements to an organic molecule

  3. Break double bonds to add the elements

  4. Adding elements to a hydrocarbon

  5. To saturate a hydrocarbon

  6. Cannot be performed on alkanes

  7. Giving space on 2 different carbons, not the same due to the double bond

  8. propan-1-ol is minor

  9. propan-2-ol is major, because 2nd C is bonded to more carbons

  10. One mole means only 1 replacement
• Substitution

  1. Swap out one element (usually a hydrogen) for another

  2. Substitutions involving alcohols will yield a water molecule

  3. Switch hydroxyl group with the other element
• primary alcohols are oxidized into aldehydes
• secondary alcohols are oxidized to ketones
• aldehydes are oxidized to carboxylic acids
• oil rig: oxidation is loss of electrons and reduction is gain of electrons
• an elimination reaction of an alkyl halide will result in an alkene and the left over halogen as a byproduct
• elimination reactions with alcohols involved result in an alkene and water as a byproduct
• the substitution reaction of benzene + Cl2 results in chlorobenzene +HCl
• the substitution reaction of CH4 + Br2 results in CH3Br + HBr