Chapter 13 Flashcards
Gas
no definite shape or volume
fill their container
Kinetic Energy
energy of motion
Kinetic Theory
All matter consists of tiny particles that are in constant motion.
What is the motion of the particles in a gas?
Rapid, constant, and random.
Will travel in a straight line until they hit something.
Random Walk
The distance between particle collisions and the direction they move afterward.
Perfectly Elastic
All particles of a gas are perfectly elastic.
The total kinetic energy after the collision remains constant.
Gas Pressure
results from the force exerted by a gas per unit surface area of an object.
Atmospheric Pressure
Results from the collisions of atoms and molecules in air with objects.
Measured with a barometer.
Depends on weather and altitude.
Sea Level
Standard Atmosphere
760 mm of Hg = 1 atm
1 atm = 101.3 kPa
STP at 0 C
SI unit for Pressure
Pascal (Pa)
Vaccum
empty space with no particles
What happens when a substance is heated?
Particles absorb energy which causes particles to move faster.
Theory of Absolute Zero
No movement for the particles.
The coldest temperature possible.
Have come within a billionth of a degree.
Based on Kelvin Scale.
Kelvin Scale
1 K = 273.15 C
How is the Kelvin temperature related to kinetic energy?
The Kelvin Temperature is directly proportional to the average kinetic energy of the particles of the substance.
Flow
high to low concentration
Fluids
Substances that can flow.
Liquids and gases.
Liquid
Definite volume but not shape.
Condensed States of Matter
Pressure on them does not really change them.
Liquids and solids.
Vaporization
going from liquid to gas vapor
Evaporation
Going from liquid to gas.
Occurs at the surface when not boiling.
Vapor Pressure
The measure of the force exerted by a gas above a liquid.
Measured by a manometer.
Equilibrium
The rate of evaporation of a liquid equals the rate of condensation rate.
Boiling Point
The temperature at which the vapor pressure of the liquid is just equal to the external pressure on the liquid.
Solids
Definite shape and volume
Melting Point
The temperature at which solid changes into a liquid.
0 C
Freezing Point
The temperature at which a liquid changes into a solid.
0 C
Crystal
3D repeating pattern
Crystal Lattice
The arrangement of particles in a solid.
Do all solids melt?
No
Ex. wood
How many groups of crystals are there?
7
Allotropes
Two or more different molecular forms of the same element.
Ex. Diamond and graphite are both pure carbon.
Amorphous Solids
Lack of an ordered internal structure.
Ex. Rubber, asphalt, plastic, glass.
These do not melt at a certain temperature but soften when heated.
Sublimation
A substance going from solid to gas without passing through the liquid state.
Ex. Dry ice and solid air fresheners.
Phase Diagram
A graph showing relationships among solids, liquids, and vapors in a sealed container.
Triple Point
A condition where substances are at equilibrium between all three states of matter.
