organic chemistry branch of chemistry dealing with carbon molecules
DESCRIPTION
Why can carbon form so many compounds? It can form up to 4 covalent bonds with other carbon atoms.TRANSCRIPT
Organic Chemistry
Branch of chemistry dealing with carbon
molecules.
Hydrocarbons
Compounds containing only carbon & hydrogen
Why can carbon form so many compounds?
It can form up to 4 covalent bonds with other carbon atoms.
What is the maximum # of bonds between any 2 C
atoms?
A triple bond (3 pairs or 6 electrons)
Properties of hydrocarbon molecules
• Molecular• Low melting points• Low boiling points• Low Hf
• Low Hv
• High evaporation rate• High vapor pressure• May be gases,
liquids, or solids
• Decompose on heating• Poor conductors of
heat & electricity• Nonpolar (vdw forces)• Dissolve in nonpolar
solvents• React slowly• Solids may be soft or
brittle
Bonding capacity of H?
1
Bonding capacity of O?
2
Bonding capacity of the halogens (F, Cl, Br, I)?
1
Bonding capacity of S?
2
Bonding capacity of N & P?
3
Bonding capacity of C?
4
The 4 single bonds of a carbon atom are directed to
…
the corners of a regular tetrahedron.
Saturated hydrocarbon
Hydrocarbon containing only single carbon-
carbon bonds
Unsaturated hydrocarbon
Hydrocarbon containing at least 1 double or triple carbon-carbon
bond
Chemical or Molecular Formulas
Tell the kind & number of atoms in a
molecule.
Structural Formulas
Tell the kind & number of atoms in a molecule. Also
attempt to show approximate shapes & bonding patterns of
molecules.
Homologous Series
A group of related compounds in which each member differs from the one before it by the
same additional unit. Properties vary in a predictable
way.
Alkanes
•Homologous series of saturated hydrocarbons. with the general formula CnH2n+2.
• Ratio of C to H is n:2n+2
Alkanes
Release energy when burned: fuels.
Naming Alkanes
•Prefix: depends on # of carbon atoms in longest continuous chain.
•Suffix: ane
Properties of Alkanes
•Nonpolar.
•Boiling point as # of carbon atoms . (van der Waals forces increase with size).
•Insoluble in water. (Like dissolves like.)
Nonpolar
•The electron cloud of the molecule is fairly evenly distributed. Either:
–Molecule has atoms with similar electronegativities–Molecule has high symmetry
Isomers
•Molecules with the same chemical formula but different structural formulas.
•Different chemical & physical properties. Different names.•Same formula mass & percentage composition.
Isomers
•# of possible isomers as # of C atoms
Alkenes
Homologous series of unsaturated hydrocarbons
containing 1 double carbon-carbon bond.
General formula of alkenes
CnH2n
Naming Alkenes
•Prefix: depends on # of carbon atoms in longest continuous chain.
•Suffix: ene
•# in front may give location of double bond.
Properties of Alkenes
Slightly more reactive than the alkanes. Double bond is site of reactivity.
Alkynes
Homologous series of unsaturated hydrocarbons containing 1 carbon-carbon triple bond.
General formula of alkynes
CnH2n-2
Naming alkynes
•Prefix: depends on # of carbon atoms in longest continuous chain.
•Suffix: yne
•# in front gives location of triple bond.