Uploaded August 2025 | Updated September 2026, 2 weeks ago
Properties of Liquids
Dr. DeBacco
Surface Tension
Caused by cohesive forces between molecules at the surface.
Molecules at the surface experience unbalanced attractions, pulling them inward.
This creates a “skin-like” effect that resists external force.
Water has high surface tension due to hydrogen bonding.
Surface Tension in Action
Water droplets forming spheres
Insects walking on water
Capillary action in plants
Viscosity
Measures a liquid’s resistance to flow.
Influenced by:
Intermolecular forces (stronger forces = higher viscosity)
Molecular size and shape
Temperature (higher temp = lower viscosity)
Viscosity Comparison
Water: low viscosity
Honey or motor oil: high viscosity
Units: Pa·s or centipoise (cP)
Structure of Water
Molecules are closely packed but not fixed in place.
Exhibit short-range order where molecules interact with neighbors but lack long-range crystalline structure.
Constant motion and collisions occur.
Properties of Water
Can adapt to container shape but maintain fixed volume.
Structure is dynamic and influenced by:
Temperature
Pressure
Type of intermolecular forces
dipole-dipole
hydrogen bonding
London dispersion
Cohesive vs. Adhesive Forces
Cohesion: attraction between like molecules
Adhesion: attraction between different substances
Ex. Water and glass
Capillary Action and Compressibility
Movement of liquid through narrow spaces due to adhesion and cohesion
Liquids are nearly incompressible due to tight molecular packing
Boiling and Freezing Points
Determined by strength of intermolecular forces
Link to Lecture Slides: drive.google.com/file/d/1TjGhTtruFkb7K_6p_QaJq3tXqAx7qlvb/view?usp=drive_link
*Due to the description character limit the full work cited for "Properties of Liquids" can be viewed at... docs.google.com/document/d/1E_q4SLZRgIDrHBboWCfKLuhzuUi87Bv8/edit?usp=drive_link&ouid=104237452697237972847&rtpof=true&sd=true
Properties of Liquids
Dr. DeBacco
Surface Tension
Caused by cohesive forces between molecules at the surface.
Molecules at the surface experience unbalanced attractions, pulling them inward.
This creates a “skin-like” effect that resists external force.
Water has high surface tension due to hydrogen bonding.
Surface Tension in Action
Water droplets forming spheres
Insects walking on water
Capillary action in plants
Viscosity
Measures a liquid’s resistance to flow.
Influenced by:
Intermolecular forces (stronger forces = higher viscosity)
Molecular size and shape
Temperature (higher temp = lower viscosity)
Viscosity Comparison
Water: low viscosity
Honey or motor oil: high viscosity
Units: Pa·s or centipoise (cP)
Structure of Water
Molecules are closely packed but not fixed in place.
Exhibit short-range order where molecules interact with neighbors but lack long-range crystalline structure.
Constant motion and collisions occur.
Properties of Water
Can adapt to container shape but maintain fixed volume.
Structure is dynamic and influenced by:
Temperature
Pressure
Type of intermolecular forces
dipole-dipole
hydrogen bonding
London dispersion
Cohesive vs. Adhesive Forces
Cohesion: attraction between like molecules
Adhesion: attraction between different substances
Ex. Water and glass
Capillary Action and Compressibility
Movement of liquid through narrow spaces due to adhesion and cohesion
Liquids are nearly incompressible due to tight molecular packing
Boiling and Freezing Points
Determined by strength of intermolecular forces
Link to Lecture Slides: drive.google.com/file/d/1TjGhTtruFkb7K_6p_QaJq3tXqAx7qlvb/view?usp=drive_link
*Due to the description character limit the full work cited for "Properties of Liquids" can be viewed at... docs.google.com/document/d/1E_q4SLZRgIDrHBboWCfKLuhzuUi87Bv8/edit?usp=drive_link&ouid=104237452697237972847&rtpof=true&sd=true
