The Nature of Gases
Define Kinetic Energy.
The energy that an object has because of motion.
Define vaporization.
The conversion of a liquid to a gas or vapor.
Fill in the blank:
All collisions between particles in a gas are _______ ________.
perfectly; elastic
Define allotropes.
They are two or more different molecular forms of the same element in the same physical state.
Define Sublimation.
The change of a substance from a solid to a vapor without passing through the liquid state.
What is the Kinetic Theory?
A theory that states that all matter consists of tiny particles that are in constant motion.
Both liquids and gases are capable of... (Hint: three answers)
Flowing freely, flowing past one another, and have kinetic energy.
What is one atm equal to?
One atm is equal to 760 mm Hg.
How are the particles in crystals arranged?
They are arranged in an orderly, repeating, three-dimensional pattern called a crystal lattice.
When can sublimation occur in solids?
It occurs in solids with vapor pressures that exceed atmospheric pressure at or near room temperature.
What results from the collisions of atoms and molecules in the air with objects?
Atmospheric pressure
What is the temperature at which the vapor pressure of a liquid is just equal to the external pressure on the liquid?
The boiling point
Fill in the blank:
In most solids, ____, ____, or ________ are tightly packed together.
atoms; ions; molecules
The _________ point is when a solid turns into a liquid and the _________ is when a liquid turns into a solid.
melting point; freezing point
What gives the condition of temperature and pressure at which a substance exists as solid, liquid, or gas (vapor)?
A phase diagram
An ____ in kinetic energy results in an ___ in temperature.
increase
What device can determine the vapor pressure of a liquid?
Manometer
What is the relationship between the temperature in kelvins and the average kinetic energy of particles?
The Kelvin temperature of a substance is proportional to the average kinetic energy of the particles.
What happens if a solid is heated?
Heating a solid make its particles vibrate more rapidly as their kinetic energy increases.
What is triple point?
It describes the only set of conditions at which phases can exist in equilibrium with one another.
What are the three assumptions of the Kinetic Theory as it applies to gases?
The particles in a gas are small and hard spheres with an insignificant volume, the motion of the particles in a gas is rapid, constant, and random, and all collisions between particles in a gas are perfectly elastic.
In a system at constant vapor pressure, a ________ exists between the vapor and the liquid. The system is in equilibrium because the rate of evaporation of liquid equals the rate of _____________.
dynamic equilibrium; condensation of vapor
What is an amorphous solid?
A solid that lacks an ordered internal structure.
What is a unit cell?
The smallest group of particles within a crystal that retains the geometric shape of the crystal.
How are the conditions represented on a phase diagram?
The conditions of pressure and temperature are indicated on a phase diagram by a line separating the two regions representing the phases.