chapter 6 keywords : electronegativity and the continuum of chemical bonding

Electronegativity

Is the relative of attraction that an atom of a molecule has for the shared pair or pairs of electrons in a covalent bonds

Polar covenant bond

Is a bond which there is unequal of the pair or pairs of electrons.

Pure covalent bonds

A bond which there is equal staring of the pair or pairs of electrons.

When do polar covalent bonds occur?

When the atoms bonded together have different electronegativity values

When do pure covalent bonds occur?

When the atoms bonded together have identical or very similar electronegativity values

Electronegativity difference for pure covalent bonding

0 - 0.4 inclusive

Electronegativity difference for a polar covalent

0.4 to 1.7 exclusive

What’s another name for pure polar covalent bonding

Non-polar covalent bonding

Electronegativity difference for covalent bonding

Less than 1.7 inclusive

Electronegativity difference for ionic bonding

More than 1.7

What is the range for the continuum of chemical bonding?

0 to 3.2

What role do Vanderwall forces play in molecules?

They play role roles in determining the boiling melting points and solubility

two conditions for a polar molecule

Bonds must be polar covalent

Molecule must be asymmetrical/lucky uniformity/bond don’t cancel out

Example examples of polar molecules

H2O water

NH3 ammonia

Non-polar molecule

Molecule That has uneven distribution of electrical charges

How do you know if a molecule is nonpolar?

It is symmetrical

Examples of nonpolar molecule shapes

Linear

Trigonal planar

Tetrahedral

Experiment to demonstrate whether a liquid is polar or non-polar

the effect of charged plastic rod on a stream of liquid

Polar liquid experiment

The liquid is attracted to the rod

The positive pills of water are attracted to the negative rod

Intramolecular bonding

Bonding that takes place within a molecule

examples of intramolecular bonding

Covalent bonding.

If there are no polar covalent bonds is the molecule polar or nonpolar

The molecule is nonpolar.

What elements are are very electronegative?

The very reactive non-metals

For a molecule to be polar what must be fulfilled?

1. Polar bonds

2. Asymettrical

What is the most electronegative element

Fluorine

What is intermolecular forces

The forces of attraction that exist between molecules

What is another name for intermolecular forces

Van Der Waals

What are van der waals forces

Weak , intermolecular forces of attraction that exist between all molecules.

Characteristic of van der Waal forces

1. Weaker than covalent bonds

2. Occur between ALL molecules

3. Strength decreases as distance increases

3 types of van der Waals

1. London dispersion forces

2. Permanent dipole-dipole forces inc hydrogen bonding

3. Ion-dipole forces

What role does van der waals Forces play

1. Boiling points

2. Melting points

3. Solubility