Unit 6 quick test

Electronegativity

A measure of an atom’s ability to attract electrons in a chemical bond.

Polarity

A condition in a bond where shared electrons are unequally distributed due to differing electronegativities.

Polar bond

A bond formed between two atoms with different electronegativities, resulting in partial charges.

Nonpolar bond

A bond where the electronegativity difference between the atoms is very small or zero.

Hydrogen Bonding

The strongest intermolecular force occurring when H is bonded to F, O, or N.

Dipole-Dipole Forces

Intermolecular forces that occur between polar molecules.

London Dispersion Forces (LDF)

The weakest intermolecular forces present in all molecules, dominant in nonpolar molecules.

Solubility

The tendency of a substance to dissolve, which is influenced by polarity (like dissolves like).

Surface Tension

A property of liquids that is higher in polar substances due to strong cohesive forces.

Capillary Action

The ability of a liquid to flow in narrow spaces against gravity, largely due to adhesion and cohesion in polar liquids.

Ionic Bonding

Strong electrostatic forces between ions in ionic compounds.

Covalent Bonding

A type of bonding where atoms share pairs of electrons; can be polar or nonpolar.

Viscosity

A measure of a fluid's resistance to flow, which is higher in substances with strong intermolecular forces.

Volatility

The tendency of a substance to vaporize; low in substances with strong intermolecular forces.

Hydrogen Bond

A strong attraction between a hydrogen atom bonded to F, O, or N and another F, O, or N atom with a lone pair.

Melting/Boiling Points

Physical properties influenced by the strength of intermolecular forces; stronger IMFs lead to higher melting/boiling points.

“Like dissolves like”

A principle stating that polar substances dissolve in polar solvents and nonpolar substances dissolve in nonpolar solvents.

Example of Polarity: H₂O

Water is a polar molecule with a partial positive charge on hydrogen and a partial negative charge on oxygen.

Boiling Point Ranking

In terms of boiling points: CH₄ (LDF) < NH₃ (Hydrogen Bonding) < H₂O (Stronger Hydrogen Bonding).

Example of Solubility: NaCl in Water

Sodium chloride (NaCl) dissolves in water due to polarity, as water is a polar solvent.