Hydrocarbons

12,194 views

Published on

Published in: Education
0 Comments
14 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
12,194
On SlideShare
0
From Embeds
0
Number of Embeds
805
Actions
Shares
0
Downloads
555
Comments
0
Likes
14
Embeds 0
No embeds

No notes for slide

Hydrocarbons

  1. 1. Organic Chemistry Introduction
  2. 2. Organic Chemistry - is the study of compounds that contain carbon.There are lots of them.90% + of known compounds are OrganicWhy?Because carbon forms chains
  3. 3. HydrocarbonsOrganic compounds that contain only hydrogen and carbon.
  4. 4. AlkanesHydrocarbons containing only single covalent bondsEx: CH4 – methane – natural gasDot diagramDashes
  5. 5. Reminders about dot diagramsOnly show 2 D shapeCarbon likes to bond in ____ placesHydrogen likes to bond in ____ place
  6. 6. Dot diagram for C2H6
  7. 7. Straight-chain alkanesContain any number of C atoms, one after the other, in a chain.You should know the names of these next alkanes
  8. 8. First 10 straight-chained alkanesMethane CH4 CH4Ethane C2H6 CH3CH3Propane C3H8 CH3CH2CH3Butane C4H10 CH3CH2CH2CH3Pentane C5H12 CH3CH2CH2CH2CH3Hexane C6H14 CH3CH2CH2CH2CH2CH3Heptane C7H16 CH3CH2CH2CH2CH2CH2CH3Octane C8H18 CH3CH2CH2CH2CH2CH2CH2CH3Nonane C9H20 CH3CH2CH2CH2CH2CH2CH2CH2CH3Decane C10H22 CH3CH2CH2CH2CH2CH2CH2CH2CH2CH3
  9. 9. Homologous seriesA group of compounds in which there is a constant increment of change in molecular structure from one compound in the series to the next.The alkanes differ by one CH2 group each timeCnH2n+2
  10. 10. Types of formulasMolecular formula – C4H10Complete structural formulaCondensed structural formula – C – H bonds are understood.Condensed structural formula – C-H and C-C bonds understoodCarbon skeleton; hydrogens understood
  11. 11. Draw a complete structural formula for thestraight-chained alkane having 3 carbons
  12. 12. Branched-chain AlkanesSubstituent – an atom or group of atoms that can take the place of a hydrogen atom on a parent hydrocarbon molecule.Parent chain – the longest carbon chain. May not always be written in a straight line on paper.
  13. 13. Alkyl group – a hydrocarbon substituentCH3 – methylCH3CH2 – ethylCH3CH2CH2 – propylAlkyl group = alkane – 1 HName = -ane + ylWhat would CH3CH2CH2 CH2be called?
  14. 14. Branched-chain alkaneAn alkane with one or more alkyl groups attached.
  15. 15. Naming a branched-chain alkane1. Find the longest chain of carbons. This is the parent chain2. # the carbons on the parent chain. Starting with the end that will give the substituents the smallest numbers3. Add #s to the names of the substituent groups to identify their positions on the chain.
  16. 16.  4. Use prefixes to indicate if a group appears more than once. Di – 2 Tri – 3 Tetra – 4 Penta – 5 5. List the names of the alkyl substituents in alphabetical order (ignore prefixes when alphabetizing.) 6. Use proper punctuation Commas separate #s from #s Hyphens separate #s from words
  17. 17. Properties of alkanesNonpolar – electrons are shared about equallyVery weak van der Walls forces (dispersion)Have a low mass, low boiling pointDo not dissolve in water.Flammable
  18. 18. Unsaturated hydrocarbons Alkenes – hydrocarbons containing carbon- carbon double covalent bonds Unsaturated compounds – organic compounds that contain double or triple C-C bonds They have fewer than the number possible of H in their structure. Saturated hydrocarbons – alkanes – all single bonds. Have the maximum number of hydrogens possible.
  19. 19. Naming alkenes1. Find the longest chain in the molecule THAT CONTAINS the double bond. (parent)2. Root name from alkane -ane +ene3. # the chain so that the double bond gets the lowest possible #. (# is listed in the name)Subsituents named just like alkanes.
  20. 20. Naming alkynesAlkynes – hydrocarbons containing C-C triple bondsNamed just like alkenes, -yne instead of –ene
  21. 21. Hydrocarbon ringsCyclic hydrocarbons – compounds that contain a hydrocarbon ring.Aliphatic compounds – do not contain ringsAromatic compounds – compounds in which the bonding is like that of benzene.
  22. 22. Naming cyclic compoundsUse the prefix cyclo before the parent name
  23. 23. Benzene3 ways to drawPhenyl – a benzene substituent
  24. 24. IsomerismStructural isomers – compounds that have the same molecular formula but different molecular structures.

×