Chapter 16 Flashcards
Particles are very close together in an orderly, fixed and usually crystalline arrangement.
Solid
An endothermic change of state in which a solid becomes a liquid
Melting
The temperature and pressure at which a solid becomes a liquid
Melting point
Have enough kinetic energy to be able to move past each other easily, take the shape of their container.
Liquid
Resistant flowing liquids
Viscous
When liquids have attraction for each other
Cohesion
Attraction for particles of solid surfaces
Adhesions
Tendency to decrease their surface area to the smallest size possible, thereby decreasing their energy.
Surface tension
Attractive forces do not have a great effect on particles, which makes the particles independent.
Gas
The temperature and pressure at which the number of liquid particles becoming gas particles is the same as the number of gas particles returning to the liquid phase
Boiling point
The temperature and pressure at which a liquid becomes a solid
Freezing point
Solid to gas
Sublimation
A gas becomes a solid without first becoming a liquid
Deposition
A region that has the same composition and properties throughout
Phase
When particles are constantly moving between two or more phases, yet no net change in the amount of the substance in either phase occurs
Equilibrium
The pressure exerted by the molecules of a gas, or vapor, in equilibrium with a liquid
Vapor pressure
A graph of the relationship between the physical state of a substance and the temperature and of the substance
Phase diagram
The temperature and pressure conditions at which the solid, liquid, and gas phases of a substance coexist at equilibrium
Triple point
Temperature and pressure at which the gas and liquid states of a substance become identical and form one phase
Supercritical fluid
Liquid and vapor phrases are indistinguishable
Critical point
Why do ionic compounds tend to have higher boiling and melting points?
They’re stronger bonds so they need more heat to break bonds
Why do molecular substances with weak intermolecular forces have low melting points?
Need less energy because they’re weak bonds
Why do molecular substances with strong intermolecular forces have high melting points?
Takes more energy to break bonds
How do dipole-dipole forces affect the melting and boiling points of substances?
Takes more energy to break bonds