carey chapter 2 hydrocarbon frameworks alkanes
play

Carey Chapter 2 Hydrocarbon Frameworks Alkanes Hydrocarbons - PowerPoint PPT Presentation

Carey Chapter 2 Hydrocarbon Frameworks Alkanes Hydrocarbons Hydrocarbons Hydrocarbons Aliphatic Aromatic Aliphatic Aromatic Aliphatic Aromatic Alkanes Alkanes Alkenes Alkenes Alkynes Alkynes Alkanes Alkenes Alkynes


  1. Carey Chapter 2 – Hydrocarbon Frameworks “Alkanes” Hydrocarbons Hydrocarbons Hydrocarbons Aliphatic Aromatic Aliphatic Aromatic Aliphatic Aromatic Alkanes Alkanes Alkenes Alkenes Alkynes Alkynes Alkanes Alkenes Alkynes

  2. 2.2-2.3 Chemical Bonding Figure 2.3 – Valence bond picture for H 2

  3. 2.2-2.3 Chemical Bonding – Two Possibilities Figure 2.5

  4. 2.4 Molecular orbitals by combining two atomic orbitals Figure 2.6

  5. 2.5 Introduction to Alkanes – Methane, Ethane, Propane Figure 2.7 CH 4 CH 3 CH 3 CH 3 CH 2 CH 3 b.p. -160 o C -89 o C -42 o C

  6. 2.6 sp 3 Hybridization and bonding in Methane Figure 2.9

  7. 2.6 sp 3 Hybridization and bonding in Methane Figure 2.10

  8. 2.7 sp 3 Hybridization and bonding in Ethane Figure 2.11

  9. 2.8 Isomeric alkanes – the Butanes Structural Isomers C 4 H 10 n -butane C 4 H 10 isobutane 2.9-2.10 Higher alkanes – the C 5 H 12 isomers C 5 H 12 C 5 H 12 C 5 H 12 n -pentane isopentane neopentane

  10. 2.10 Higher alkanes – diversity

  11. Careful with drawing chains! CH 3 CHCH 2 CH 3 CH 3 CH 2 CHCH 3 CH 3 CH 3 CH 3 CH 3 CHCH 2 CH 3 CH 3 CH 3 CH 2 CH 2 CH 3 CH 3 CH 2 CHCH 3 CH 3 All the same compound

  12. 2.11-2.12 Alkane nomenclature Need to know up to C-12

  13. 2.11-2.12 Alkane nomenclature IUPAC Rules: • Find the longest continuous carbon chain • Identify substituent groups attached to the chain • Number the chain so as to keep numbers small • Write the name in the following format: Numerical location - [substituent(s)][parent alkane] e.g. 2,3-dimethylheptane

  14. 2.12 IUPAC Rules and how to apply them Hexane (IUPAC); n -hexane (common) Longest chain - hexane substituent - meth yl position on chain - 2 2-methylhexane not 5-methylhexane 3,4-dimethylheptane

  15. 2.13 Alkyl groups Replace -ane ending with -yl H C C C C C C C C H H C primary (1 o ) secondary (2 o ) tertiary (3 o ) CH 3 H H H CH 3 H C C C CH H 3 C C CH 3 H H H CH 3 (CH 3 ) 3 C CH 3 CH 2 CH 2 (CH 3 ) 2 CH propyl group isopropyl group t -Butyl group 1-methylethyl 1,1-dimethylethyl

  16. 2.14 Highly branched alkanes 4-ethyloctane 4-ethyl-3-methyloctane 4-ethyl-3,5-dimethyloctane

  17. 2.15 Cycloalkanes 1,1,3-trimethylcyclohexane 2-ethyl-1,1- dimethylcyclopentane C(CH 3 ) 3 (notice the “di” is not (1,1-dimethylethyl)cycloheptane involved in the alphabetization)

  18. 2.16 Sources of alkanes and cycloalkanes Figure 2.12

  19. 2.17 Physical properties Figure 2.15

  20. 2.17 Physical properties – branched alkanes Figure 2.16

  21. 2.18 Chemical properties of Alkanes Alkane properties : • Generally very insoluble in water (“greasy” or “oily”) • Individual molecules interact via van der Waals forces • These intermolecular forces decrease with branching • Alkanes may be combusted in oxygen: CO 2 + 2H 2 O ∆ H = - 213 kcal e.g. CH 4 + 2O 2 i.e combustion of hydrocarbons releases energy

  22. 2.18 Heats of combustion – Figure 2.17

  23. 2.19 Oxidation-Reduction in Organic Chemistry

  24. 2.20 sp 2 Hybridization in ethylene Figure 2.18 H H C C H H

  25. 2.20 sp 2 Hybridization in ethylene Figure 2.19

  26. 2.20 sp 2 Hybridization in ethylene Figure 2.20

  27. 2.21 sp Hybridization in ethylene Figure 2.21

  28. 2.21 sp Hybridization in acetylene Figure 2.22

  29. 2.21 sp Hybridization in acetylene Figure 2.23

Recommend


More recommend