Introduction to Organic
Chemistry
CHEM 2124 – General Chemistry II
Alfred State College
Professor Bensley
Learning Objectives
 Recognize the characteristic features of
organic compounds.
 Predict the shape around atoms in organic
molecules.
 Use shorthand notation to draw organic
molecules.
 Recognize the common functional groups
and understand their importance.
Learning Objectives
 Distinguish organic compounds from ionic
inorganic compounds.
 Determine whether or not an organic
compound is polar or non-polar.
 Determine solubility properties of organic
compounds.
I. Introduction to Organic Chemistry
Organic chemistry is the study of compounds that
contain the element carbon.
II. Characteristics of Organic Compounds
1. All organic compounds contain carbon atoms and
most contain hydrogen atoms.
2. Carbon forms single, double, and triple bonds to
other carbon atoms.
3. Some compounds have chains of atoms and some
compounds have rings.
II. Characteristics of Organic Compounds
4. Organic compounds may also contain elements
other than carbon and hydrogen.
THE RULE OF “HONC”
III. Drawing Organic Molecules
A. Condensed Structures
•Some bond lines can be drawn in for effect or to
show specific bonding.
III. Drawing Organic Molecules
A. Condensed Structures
•Identical groups can be condensed further:
III. Drawing Organic Molecules
B. Skeletal Structures
IV. Functional Groups
A. Hydrocarbons
•Alkanes
•Alkenes
•Alkynes
•Aromatics
B. Compounds Containing a Single Bond to a
Heteroatom
C. Compounds Containing a C=O (Carbonyl) group
V. Properties of Organic Compounds
V. Properties of Organic Compounds
A. Polarity
•A covalent bond is nonpolar when two atoms of
identical or similar electronegativity are bonded.
•If the individual polar
bonds (dipoles) cancel
in a molecule, the
molecule is nonpolar.
•If the individual bond
dipoles do not cancel, the
molecule is polar.
V. Properties of Organic Compounds
B. Solubility
•The rule of solubility is “like dissolves like.”
CH3CH2CH2CH2CH2CH3
hexane
•small nonpolar molecule
•no O or N present
•H2O insoluble
•organic solvent soluble
CH3CH2—OH
ethanol
•small polar molecule
•O atom present
•H2O soluble
•organic solvent soluble
cholesterol
VI. Shapes of Organic Molecules
VSEPR theory: The most stable arrangement keeps
the groups on a central atom as far away from each
other as possible.
VI. Shapes of Organic Molecules
To draw a 3-D tetrahedron in 2-D, we use:
•a solid line for bonds in the plane
•a wedge for a bond in front of the plane
•a dashed line for a bond behind the plane