Properties of Liquids (10.2) Flashcards
- Distinguish between adhesive and cohesive forces. - Define viscosity, surface tension, and capillary rise. - Describe the roles of intermolecular attractive forces in each of these properties/phenomena.
What is liquid viscosity?
A measure of a liquids resistance to flow. We can measure how viscous a liquid is by how fast an object has fallen down to the bottom of a liquid. (more viscous = object falls down more slowly)
What determines the viscosity of liquid?
- IMFs between molecules of liquid.
- Size and shape.
- Temperature
Viscosity is measure in mPa x s
What is cohesive/cohesion?
The attractive force between molecules in the same substance.
Example: Water molecules sticking to other water molecules
Cohesive/Cohesion: Molecules sticking to each other.
What is adhesive/adhesion?
The attractive force between molecules and different substances. These forces causes a substance to stick to another one.
Example: Water sticking to surface of glass.
Adhesive/Adhesion: Molecules sticking to something else.
What is a capillary action?
When liquid flows within a porous material due to the attraction of liquid molecules to surface of the material and to other liquid molecules.
Example: Paper towel picking up a spill, water attracted to towel when wiping on surface of skin.
The adhesive force and cohesive force combined when using a porous material may attract so much to where gravity is resisted when attracted.
How far can a liquid go up on a capillary tube?
Depending on the diameter of tube and type of fluid.
