Zusammenfassung der Ressource
Reactions
- Alkanes
- Combustion
- Exothermic
- Non-Toxic Products
- Example...
Anmerkungen:
- C3H8 + 5O2 ===> 3CO2 + 4H2O
- Halogenation
- Under UV Radiation
- Free Radical Mechanism
- Propagation
- Initiation
- Termination
- Mixture of Products
- Example...
Anmerkungen:
- CH4 +CL2 =UV=> CH3CL + HCL
CH3CL+CL2 =UV=> CH2CL2 +HCL etc...
- Alkenes
- Combustion
- Exothermic
- Smoky Flame
- Example...
Anmerkungen:
- 2C3H6 + 9O2 ===> 6CO2+6H2O
- Electrophilic Addition
- Bromination
- With Bromine
- Example...
Anmerkungen:
- H2C=CH2 + Br2 ===> Br-H2C-CH2-Br
(dibromoalkane)
- With Bromine Water
- Example...
Anmerkungen:
- H2C=CH2 + Br2 + H2O ===> Br-H2C-CH2-OH + HBr
(bromoalcohol)
- Test for alkene
- Decolourises
- Can be in dark
- Hydrobromination
- Example...
Anmerkungen:
- Major Product
Anmerkungen:
- Minor Product
Anmerkungen:
- Catalytic Addition
- Hydrogenation
- Example...
Anmerkungen:
- H2C=CH2 + H2 =Pt, High Temp, High Pressure=>H3C-CH3
- Hydration
- Ethanol Manufacture
- Example...
Anmerkungen:
- H2C=CH2(g) + H2O(g) =H3PO4, High Pressure, 300C=> H3C-CH2-OH
- Oxidative Addition
- Test for alkenes
- Example...
Anmerkungen:
- H2C=CH2 + [O] + H2O [O]=KMnO4, Acid/Alkali=> HO-H2C-CH2-OH
(diol)
If acid, purple is decolourised. If alkali, purple goes green
- Addition Polymerisation
- Free Radical Mechanism
- Example...
Anmerkungen:
- n H2C=CH2 =catalyst, pressure=> -(-H2C-CH2-)-n
poly(ethene)
- Halogenoalkanes
- With Ammonia
- Example...
Anmerkungen:
- R-X + NH3 =xs NH3, pressure, closed vessel=> R-NH2 + HX
(primary amine) An additional mole of ammonia is required to react with HX formed.
PTO for competing reaction...
- R-X + R-NH2 ===> R2NH + HX
(secondary amine)
- With Aqueous KOH
- Test For R-X
Anmerkungen:
- Neutralise with HNO3
Add AgNO3
- White Precipitate:- R-Cl
- Cream Precipitate:- R-Br
- Yellow Precipitate:- R-I
- Example...
Anmerkungen:
- R-X + OH^- =aqueous KOH=> R-OH + X^-
- Rate
- R-I > R-Br > R-Cl
- Tert. > Secd. > Pri.
- With Ethanolic KOH
- Elimination of HX
- Example...
Anmerkungen:
- H3C-CH2X + OH^- =ethanolic KOH=>
H2C=CH2 + H2O + X^-
- Alcohols
- With Sodium
- Example...
Anmerkungen:
- 2C3H7OH +2Na ===> 2C3H7O^-Na^+ H2
(sodium propoxide)
- Dehydration
- Example...
Anmerkungen:
- C3H7OH =conc. H2SO4=> H3C-HC=CH2 + H2O
(alkene)
- Halogenation
- With Phosphorous trihalides
- Examples...
Anmerkungen:
- For chloroalkane...
3C3H7OH + PCl3 ==> 3C3H7Cl +H3PO3
- For bromoalkane...
3C3H7OH + P + 1.5Br2 =heat under reflux=> 3C3H7Br +H3PO3
- For iodoalkane...
3C3H7OH + P + 1.5I2 =heat under reflux=> 3C3H7I +H3PO3
- With PCl5
- Test For OH Group
- Example...
Anmerkungen:
- C3H7OH + PCl5 ==> C3H7Cl + POCl3 + HCl
(steamy fumes, turn damp litmus paper red)
- With Thionyl Chloride
- Makes For Easily Purifiable Halogenoalkanes
- Example...
Anmerkungen:
- C3H7OH + SOCl2 ==> C3H7Cl + SO2(g) + HCl(g)
- With Hydrogen Halides
- Examples...
Anmerkungen:
- For chloroalkane...(CH3)3C-OH + HCl =conc. HCl=> C3H7Cl + H2O
(only with tertiary alcohols)
- For bromoalkane...C3H7OH + HBr =NaBr, conc. H2SO4, distill product=>
C3H7Br +H2O
- For iodoalkane...
C3H7OH +HI =KI, conc. H3PO4, distill product=> C3H7I + H2O
- Oxidation
- Primary
Anmerkungen:
- R-CH2-OH + [O] =distilling=> R-C(=O)(-H)
(aldehyde) [O] = K2Cr2O7
PTO if not distilled...
- R-CH2-OH + 2[O] =boil under reflux=> R-C(=O)(-OH)
(carboxylic acid)
- Secondary
Anmerkungen:
- R2CH-OH + [O] ==> R-C(=O)(-R)
(ketone)
- Tertiary
Anmerkungen:
- R3C-OH + [O] ==> no reaction