1. Properties of Organic and Inorganic Compounds
Experiment 1
Chem 121
Organic Chemistry Laboratory

2. What is ORGANIC CHEMISTRY?

3. Introduction Vital force – ‘vitalism’
Friedrich Wohler overthrew vitalism
Synthesis of urea from ammonium cyanate
Distinguishing feature: organic compounds all contain the CARBON atom

4. What is ORGANIC chemistry?
the study of carbon containing compounds
Other elements in organic compounds: H, O, N, S, P, Cl, Br, I and other transition metals
Why Carbon?
Can share four valence electrons
Form strong covalent bonds
Form rings and long chains, e.g. benzene and DNA

5. Definition of terms
Ionic compounds: compounds made up of a metal cation and a nonmetal anion
e.g. NaCl, KNO3
Intramolecular forces of attraction: forces existing within molecules that holds the atoms together
e.g. Ionic bond, covalent bond, metallic bond
Intermolecular forces of attraction: forces existing between molecules

6. Intermolecular Forces of Attraction
Ion-dipole
Between an ionic compound and a polar compound
e.g. NaCl dissolved in water
Dipole-dipole
Between two polar compounds
e.g. HCl dissolved in water

7. London dispersion forces/van der Waals forces
Hydrogen Bonding
Requirement: H atoms bonded to F, O, N
Strongest intermolecular force
e.g. NH3 in H2O
London dispersion forces/van der Waals forces
Between two NONPOLAR compounds
Weakest intermolecular force; present in all organic molecules

8. The larger the size of the organic compound, the larger the London dispersion forces.

9. Properties of Organic Compounds
Flammable
Due to the C-C bond energies in organic compounds
Energy released is in the form of heat
Ethanol vs. Water
Ethanol – produces the distinct blue flame
Water – smothers flame instead of generating one

10. Charring Sucrose also known as burning, scorching
organic compounds are sensitive to heat
End result of charring: elemental C
Sucrose
disaccharide
common ingredient in sweet foods like ice cream, candy
also works as a food preservative

11. IMF of sucrose: London dispersion force
IMF of NaCl and CaCO3: no intermolecular force, but intramolecular (IONIC BOND)
Remember always: Intramolecular forces are way STRONGER than intermolecular forces.

12. Solubility relies on the intermolecular forces of organic compounds
‘like dissolves like’
Polar solvents dissolve in polar solutes.
Nonpolar solvents dissolve in nonpolar solutes.
Organic compounds = mostly nonpolar
It only follows that most organic compounds are soluble in organic solvents.

13. Naphthalene in water Naphthalene in ether
No ionic bonds, just pure London dispersion forces
Naphthalene in water
Water is capable of hydrogen bonding; naphthalene cannot

14. Electrical Conductivity
Electrical conductivity is only possible when a compound contains charged particles (i.e. an electrolyte)
e.g. NaCl, NaNO3 are electrolytes
Since most organic compounds are molecular, not ionic, it does not conduct electricity.

15. 1 M sucrose
1 M ethanol
1 M NaCl
hexane

16. Summary Organic chemistry is the study of carbon compounds.
Organic compounds have the ff properties:
Flammable
Combustible
Immiscble in polar solvents like water
Non-electrolytes; do not conduct electricity