Week 7_physiochemical properties

Physical Property

• A property that does not affect the chemical identity of a compound

• Can be observed and measured without changing a compound’s composition of matter

  – Any substance that has mass and can occupy space

1. Intrinsic

2. Extrinsic

2 Types of Physical property

1. INTRAmolecular forces

2. INTERmolecular forces

Molecular Forces 2 TYPES

INTRAmolecular forces

Strong Types of molecular forces

INTRAmolecular forces

within ATOM

1. Ionic

2. Covalent

3. Metallic

INTRAmolecular forces 3 TYPES

Covalent

Weak type of INTRAmolecular forces

Metallic

Strong type of INTRAmolecular forces

INTERmolecular forces

Within MOLECULE

1. Vander waals

2. Ion-Dipole

3. Hydrogen bond

INTERmolecular forces 3 Types

Van der Waals

Weak type of INTERmolecular forces

Hydrogen Bonding

Strong type of INTERmolecular forces

1. Keesom

2. Debye

3. London dispersion

3 types of VAN DER WAALS

Dipole - Dipole

other term for KEESOM

Dipole - Induced Dipole

other term for DEBYE

Induced Dipole - Induced Dipole

other term for LONDON DISPERSION

London Dispersion

Weak type of Vander waals

DIPOLE

other term for POLAR

Homolytic Fission

The fission of a covalent bond with equal sharing of bonding electrons.

Heterolytic Fission

The fission of a covalent bond involving unequal sharing of bonding electrons

5-25 kJ/mol

what is the IMF’s range of HYDROGEN BONDING

5-10 kJ/mol

what is the IMF’s range of DIPOLE-DIPOLE

2-5 kJ/mol

what is the IMF’s range of LONDON DISPERION

FON

What are the elements connected in Hydrogen bonding that have a LONE PAIR e-

Hydrogen bonding

is a complex interaction that includes dipole-dipole, as well as orbital interactions and the transfer of electron density between molecules

Dipole-dipole forces

• arise from the attraction of oppositely charged atoms (other than H) in molecules. These molecules may have a permanent dipole moment.

• Generally in organic molecules they result from the presence of C-X bonds where X is more electronegative to that of C.

London dispersion

• forces arise from the movement of electrons within a molecule. This natural motion can produce an uneven distribution of the electrons (polarization of the distribution) resulting in a temporary dipole moment in the molecule.

• This will induce the movement of electrons in adjacent molecules producing a dipole moment in them.

alcohols, amines

Any functional group that can donate a hydrogen bond to water ——

will significantly contribute to water solubility.

ketones, aldehydes, ethers

Any functional group that can only accept a hydrogen bond from water ——

will have a somewhat smaller but still significant effect on water solubility

alkyl halides, thiols, sulfides

groups that contribute to polarity ——

will make a small contribution to water solubility.

Boiling and melting point

are processes in which noncovalent interactions between identical molecules in a pure sample are disrupted.

Methane

What is the lowest melting point with -182.5 c and

boiling points with -167.7 c

Triacontane

What is the heights melting point with 449.7 c and

boiling points with 65.8 c

chemical reaction

• occurs when one substance is converted into another substance(s).

• it is accompanied by breaking of some bonds and by making of some others.

Free radicals

are neutral but reactive species having an unpaired electron and these can also initiate a chemical reaction

carbocation

an ion which has a positive charge on the carbon atom, is known as the?

carbanion

an ion with a negative charge on the carbon atom is known as the?

Electrophiles:

is an electron deficient species and it may be positively charged or neutral.

• Examples are H+ , AlCl3 , Br2 , Cl2 , Ag+ , CH3+, BF3 etc. –

Nucleophiles

is negatively charged or electron rich neutral species.

• Examples are OH–, –NO2+ , H2O, :NH3 etc.

Elimination

characterized by the removal of a small molecule from adjacent carbon atoms and the formation of a double bond.

Addition

Unsaturated hydrocarbons such as alkenes and alkynes are extremely reactive towards a wide variety of reagents. The carbon-carbon double bond (–C=C–) of an alkene contains two types of bonds. In alkynes, three carbon-carbon bonds.

molecular Rearrangements

– proceeds with a fundamental change in the hydrocarbon skeleton of the molecule. During this reaction, an atom or group migrates from one position to another.

Elimination

Addition

Molecular rearrangements