Gen chem

Intermolecular Forces

• Hydrogen Bonding: Strong force between a

hydrogen atom and a highly electronegative

atom like oxygen.

• Dipole-Dipole: Attraction between polar

molecules.

• London Dispersion Forces: Weak forces from

temporary dipoles in molecules.

Molecular Properties Affected by

Bonds

• Boiling Point: Affected by the type of bond and

intermolecular forces (e.g., hydrogen bonding

raises boiling point).

• Surface Tension: Water has high surface

tension due to hydrogen bonding.

Types of Solids

• Crystalline Solids: Regular arrangement of

particles, sharp melting points.

• Amorphous Solids: Lack a defined shape, no

sharp melting points.

Vapor Pressure and Boiling Point

• Vapor pressure increases with temperature.

• Higher vapor pressure = Lower boiling point.

Phase Changes

• Melting: Solid to liquid

• Boiling: Liquid to gas

• Sublimation: Solid to gas

• Deposition: Gas to solid

Solution Chemistry

• Homogeneous Mixtures: Sugar in water.

• Increase solubility by heating or stirring.

• Vapor pressure of a solution is lower than that of the pure solvent.

nthalpy and Reaction Types

• Exothermic Reactions: Release heat

(temperature of surroundings increases).

• Endothermic Reactions: Absorb heat

(temperature of surroundings decreases).

• Calorimeters are used to measure enthalpy

changes.