states of matter liquids. states of matter objectives describe the motion of particles in liquids...
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States of Matter Objectives
Describe the motion of particles in liquids and the properties of liquids according to the kinetic-molecular theory
Discuss the process by which liquids can change into a gas and define vaporization
Discuss the process by which liquids can change into a solid and define freezing
States of Matter Properties of Liquids and the Kinetic-Molecular Theory
A liquid can be described as a form of matter that has a definite volume and takes the shape of its container
The attractive forces between particles in a liquid are more effective than those between particles in a gas
This attraction between liquid particles is caused by the intermolecular forces:
dipole-dipole forces London dispersion forces hydrogen bonding
States of Matter Properties of Liquids and the Kinetic-Molecular Theory
The particles in a liquid are not bound together in fixed positions. Instead, they move about constantly
A fluid is a substance that can flow and therefore take the shape of its container
States of Matter Properties of Liquids and the Kinetic-Molecular Theory
Relatively High Density
At normal atmospheric pressure, most substances are hundreds of times denser in a liquid state than in a gaseous state
States of Matter Properties of Liquids and the Kinetic-Molecular Theory
Relative Incompressibility
Liquids are much less compressible than gases because liquid particles are more closely packed together
States of Matter Properties of Liquids and the Kinetic-Molecular Theory
Ability to Diffuse
Any liquid gradually diffuses throughout any other liquid in which it can dissolve
The constant, random motion of particles causes diffusion in liquids
Diffusion is much slower in liquids than in gases because liquid particles are closer together
The attractive forces between the particles of a liquid slow their movement
As the temperature of a liquid is increased, diffusion occurs more rapidly
States of Matter Properties of Liquids and the Kinetic-Molecular Theory
Surface Tension
A property common to all liquids is surface tension, a force that tends to pull adjacent parts of a liquid’s surface together, thereby decreasing surface area to the smallest possible size
The higher the force of attraction between the particles of a liquid, the higher the surface tension
The molecules at the surface of the water can form hydrogen bonds with the other water, but not with the molecules in the air above them
States of Matter Properties of Liquids and the Kinetic-Molecular Theory
Surface Tension
Capillary action is the attraction of the surface of a liquid to the surface of a solid
This attraction tends to pull the liquid molecules upward along the surface and against the pull of gravity
The same process is responsible for the concave liquid surface, called a meniscus, that forms in a test tube or graduated cylinder
States of Matter Properties of Liquids and the Kinetic-Molecular Theory
Evaporation and Boiling
The process by which a liquid or solid changes to a gas is vaporization
Evaporation is the process by which particles escape from the surface of a non-boiling liquid and enter the gas state
Boiling is the change of a liquid to bubbles of vapor that appear throughout the liquid
Evaporation occurs because the particles of a liquid have different kinetic energies