Chapter 12

Question 1

phase

Answer 1

A physically distinct and homogeneous part of a system

Question 2

intermolecular forces

Answer 2

The attractive and repulsive forces among the particles- molecules, atoms, or ions- in a sample of matter.

Question 3

phase change

Answer 3

A physical change from one phase to another, usually referring to a change in physical state

Question 4

condensation

Answer 4

The process of a gas changing into a liquid

Question 5

vaporization

Answer 5

The process of changing from a liquid to a gas

Question 6

freezing

Answer 6

The process of cooling a liquid until it solidifies

Question 7

melting(fusion)

Answer 7

The change of a substance from a solid to a liquid

Question 8

sublimation

Answer 8

The process by which a solid changes directly into a gas

Question 9

deposition

Answer 9

The process of changing directly from gas to solid

Question 10

heat of vaporization

Answer 10

The enthalpy change occurring when 1 mol of a liquid substance vaporizes.

Question 11

heat of fusion

Answer 11

The enthalpy change occurring when 1mol of a solid substance melts

Question 12

heat of sublimation

Answer 12

The enthalpy changes occurring when of a solid substance changes directly to a gas.

Question 13

heating-cooling curve

Answer 13

A plot of temperature vs. time for a substance when heat is absorbed or released by the system at a constant rate

Question 14

dynamic equilibrium

Answer 14

The condition at which the forward and reverse relations are taking place at the same rate, so there is no net change in the amounts of reactants or products

Question 15

vapor pressure

Answer 15

The pressure exerted by a vapor at equilibrium with its liquid in a closed system

Question 16

Clausius-Clapeyron equation

Answer 16

An equation that expresses the linear relationship between vapor pressure P of a liquid and temperature T.

Question 17

boiling point

Answer 17

The temperature at which the vapor pressure of a gas equals the external pressure

Question 18

melting point

Answer 18

The temperature at which the solid and liquid forms of a substance are at equilibrium

Question 19

phase diagram

Answer 19

A diagram used to describe that stale phases and phase changes of a substance as a function of temperature and pressure

Question 20

triple point

Answer 20

The pressure and temperature at which three phases of a substance are in equilibrium. In a phase diagram, the point at which three phase-transition curves meet.

Question 21

critical point

Answer 21

The point on a phases diagram above which the vapor cannot be condensed to a liquid; the end of the liquid-gas curve

Question 22

van der Waals radius

Answer 22

One-half of the shortest distance between the nuclei of identical non bonded atoms

Question 23

ion-dipole force

Answer 23

The intermolecular attractive force between an ion and a polar molecule.

Question 24

dipole-dipole force

Answer 24

The intermolecular attraction between oppositely charged poles of nearby polar molecules

Question 25

hydrogen bond

Answer 25

A type of dipole-dipole force that arises between molecules that have an H atom bonded to a small, highly electronegative atom with lone pairs, usually N,O, or F.

Question 26

polarizability

Answer 26

The ease with which a particle’s electron cloud can be distorted

Question 27

dispersion force

Answer 27

The intermolecular attraction between all particles as a result of instantaneous polarizations of their electron clouds; the intermolecular force primarily responsible fro the condensed states of non polar substances