2.  So far in this unit we have discussed hydrocarbons and their isomers  We have also learned about organic compounds with different functional groups  Throughout this we have learned naming rules for each  Now we are going to focus on several types of organic reactions

3.  There are many types of organic reactions  We are only going to focus on a few. › Substitution › Elimination › Addition › Esterification

4.  Any reaction in which one atom is replaced by another  Used to place a halogen onto an alkane  The products are always a halocarbon and the acid of the halogen  Reaction requires ultraviolet light to initiate the reaction › This provides the energy needed to form the excited state

5. ethane + chlorine  chloroethane + hydrochloric acid The Cl atom will replace a H atom resulting in an alkyl halide and the acid of the halogen (hydrochloric acid)

6.  You can also have an alcohol react with a halogen resulting in an alkyl halide and water Ethanol + hydrochloric acid  chloroethane + water

7.  Any reaction in which atoms are eliminated from another molecule  Done in three ways: › Elimination of H 2 › Elimination of HX › Elimination of H 2 O

8.  Called dehydrogenation  Occurs in the presence of a base (eg. NaOH) and heat ethane  ethene + hydrogen

9.  Alkyl halides undergo elimination reaction  This is known as dehydrohalogenation  Occurs in the presence of a base Base extracts H + and X - will leave; resulting in double bond formation

10.  Alcohol can undergo elimination via the loss of water  Known as dehydration a) Acid protonates the OH group, water leaves and C + remains behind b) An adjacent H + leaves next leaving electron pair to form double bond

11.  Takes place with unsaturated compounds which are usually more reactive than saturated compounds  Takes place with double and triple bonds  Two atoms are added across the electron rich bond  Four types of addition: › Addition of X 2 (halogen) › Addition of H 2 › Addition of H 2 O › Addition of HX (hydrogen halide)

12.  Normally occurs in dissolved solvents such as CCl 4  Alkenes form dihaloalkanes  Alkynes produce dihaloalkenes or tetrahaloalkanes ethene + chlorine  1,2-dichloroethane

13.  Catalysts used such as Pt, Pd or Ni  Known as hydrogenation  Alkene becomes alkane  Alkyne becomes alkene or alkane ethene + hydrogen  ethane

14. ethyne + hydrogen  ethene ethyne + (2 mol) hydrogen  ethane

15.  Occurs in the presence of an acid  Know as hydration  Alkene becomes alcohol  Alkyne produces ketone or aldehyde ethene + water  ethanol

16.  HX = HCl or HBr or HI (NOT HF)  Alkene becomes alkyl halide  Alkynes form monohalo alkenes or dihalo alkanes (with halogen on the same C)  Rule for adding H and X › The halogen (X) will always add to the more substituted carbon atom – the carbon that is bonded to the most carbon atoms

17. 1-propene + hydrobromic acid  2-bromopropane Step1: 1-propyne + hydrobromic acid  2-bromo-1-propene Step 2: 2-bromo-1-propene+ hydrobromic acid  2,2-dibromopropane

18.  Alcohol + organic acid  water + ester  Used to make perfumes, scents and flavours  Combination reaction which involves dehydration  Alcohol becomes the alkyl group and the acid becomes -oate

19. propanol + ethanoic acid  propyl ethanoate + water