45 terms

Chemistry Ch 13

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Terms in this set (...)

the energy an object has because of its motion
kinetic energy
T/F: a gas is composed of particles with insignificant volume that are relatively far apart from each other
True
T/F: Strong attractive forces exist between particles of a gas
False
T/F: The paths of uninterrupted travel of particles in a gas are relatively short because the particles are constantly colliding with each other or with other objects
True
T/F: According to the kinetic theory, collisions between particles in a gas are perfectly elastic because kinetic energy is transferred without loss from one particle to another, and the total kinetic energy remains constant.
True
Gas pressure results from the force exerted by a gas per...
unit surface area of an object
Simultaneous collisions of billions of particles in a gas with an object result in...
gas pressure
What force holds the particles of air in the Earth's atmosphere?
gravity
What kind of pressure is measured with a barometer?
Atmospheric pressure
Units of measure for atmospheric pressure
1 atm; 101,350 Pa; 101.3 kPa; 760 mmHg; 760 torr; 14.7 pounds per square inch
a temperature of 0 degrees Celsius and a pressure of 101.3 kPa, or 1 atm
standard temperature and pressure (STP)
What happens to the temperature of a substance when the average kinetic energy of its particles increases?
an increase of temperature
T/F: All the particles in a substance at a given temperature have the same kinetic energy.
False
temperature 0K or -273.15 degrees Celsius (theoretically, particles of matter at this temperature would have no energy)
absolute zero
What temperature scale is directly proportional to the average kinetic energy of the particles of a substance.
Kelvin
T/F: The kinetic theory states that there are no attractions between the particles of a liquid.
False
T/F: Liquids are much denser than gases because intermolecular forces reduce the amount of space between the particles in a liquid.
True
T/F: Increasing pressure on a liquid has hardly any effect on its volume.
True
T/F: Liquid particles are free to slide past one another.
True
the conversion of a liquid to a gas or vapor
vaporization
the process when vaporization occurs at the surface of a liquid that is not boiling
evaporation
T/F: Evaporation is a cooling process because the particles in a liquid with the highest kinetic energy tend to escape first, leaving the remaining particles with a lower average kinetic energy and, thus, a lower temperature.
True
T/F: Vapor pressure arises when particles of a liquid in a closed, partly filled container vaporize and collide with the walls of the container.
True
T/F: After a time in a close, partly filled container, a liquid will evaporate and its vapor will condense at equal rates.
True
T/F: When the temperature of a contained liquid increases, its vapor pressure increases.
True
The boiling point of a liquid is the temperature at which the vapor pressure of the liquid is just equal to the...
external pressure on the liquid
Why does boiling point decrease as altitude increases?
there is less air pressure on top of the liquid so it is easier for the vapor pressure in the liquid to equal the atmospheric pressure
T/F: After a liquid reaches its boiling point, its temperature continues to rise until all the liquid vaporizes.
False
T/F: Although particles in solids have kinetic energy, the motion of particles in solids is restricted to vibrations about fixed points.
True
T/F: the temperature at which the liquid and solid states of a substance are in equilibrium is the same as the melting point and the freezing point of the substance.
True
When does a solid melt?
when its particles vibrate more rapidly and the organization of the particles within the solid breaks down
How are particles arranged in a crystal?
in an orderly, repeating, three dimensional pattern
What type of solid has a relatively low melting point?
molecular solids
Do all solids melt when heated?
no, wood and cane sugar decompose when heated
T/F: Most solid substances are not crystalline.
False
T/F: All crystals have sides, or faces, that intersect at angles that are characteristic for the given substance.
True
T/F: There are seven groups, or crystal systems, into which all crystals may be classified.
True
T/F: The orderly array of sodium ions and chloride ions gives crystals of table salt their regular shape.
True
T/F: Some solid substances can exist in more than one form.
True; carbon can be graphite, diamond, or charcoal
Two or more different molecular forms of the same element in the same physical state
allatropes
What is an amorphous solid?
a solid that lacks an ordered internal structure
Examples of amorphous solids
plastic, glass, rubber
Face change from solid to gas without going through a liquid faze
sublimation
T/F: Solids have vapor pressure because some particles near the surface of a solid substance have enough kinetic energy to escape directly into the vapor phase.
True
What is the triple point?
a point that describes the only set of conditions at which all 3 phases can exist in equilibrium with one another