Acc. Chemistry Chapter 13

-pressure:

1 atmosphere; 101.3 kPa; 760 mmHg;760 torr -when barometric pressure increases(hot and dry) -when barometric pressure decreases (wold and wet)

True about the particles of a liquid(3)

1. Liquids are much denser than gases because intermolecular forces reduce the amount of space between the particles in a liquid. 2. Increasing pressure on a liquid has almost no effect on its volume. 3. Liquid particles are free to slide past one another.

*What factors determine the physical properties of a liquid?

1. The interplay between the disruptive motions of particles in a liquid 2.the attractions among the particles

*What are the three assumptions of the kinetic theory as it applies to gases?

1. The particles in a gas are considered to be small, hard, spheres with an insignificant volume 2. The motion of the particles in a gas is rapid, constant, and random 3. All collisions between particles in a gas are perfectly elastic

True about solids(3):

1. all crystals have sides, or faces, that intersect at angles that are characteristic for a given substance 2. There are seven groups, or crystal systems, into which all crystals can be classified 3. The orderly array of sodium ions and chloride ions gives crystals of table salt their regular shape

every name of a unit of pressure(3)

1. mmHG 2. kPa 3. atm

Examples of solids that are amorphous solids:

1. rubber 2. plastic 3. glass 4. Silly putty

true about the assumptions of the kinetic theory concerning gases.

1.A gas is composed of particles with insignificant volume that are relatively far apart. 2.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 about vapor pressure(3):

1.Vapor pressure exits when particles of a liquid in a closed, partly filled container vaporize and collide with the walls of the container 2. After a time in a closed, partly filled container, a liquid will evaporate and its vapor will condense at equal rates 3.Whn the temp. of a contained liquid increases, its vapor pressure increase

Standard pressure

= 1atm = 101.3 kPa = 760mmHg = 760 torr

What does a phase diagram show?

A phase diagram shows the temperature and pressure conditions at which a substance exits in the solid, liquid, and vapor phases

Gas/vapor to Liquid =

Condensation

Name of phase change of a gas to a solid =

Deposition

*What is the relationship between evaporation and kinetic energy?

During evaporation, only those molecules with a certain minimum kinetic energy can escape from the surface of the liquid.

Name of phase change of a liquid to a gas =

Evaporation/Vaporization

Liquid to solid =

Freezing

*How does kinetic theory explain gas pressure?

Gas pressure is the result of billions of rapidly moving particles in a gas simultaneously colliding with an object

-Evaporation:

Gets kinetic energy from collisions with other particles and collisions with other containers

*why can a dynamic equilibrium exist between a liquid and its vapor?

In a system at constant vapor pressure, a dynamic equilibrium exists between the vapor and the liquid.- *The system is in equilibrium because the rate of evaporation of liquid equals that rate of condensation of vapor.

Name of phase change of a solid to a liquid =

Melting

Solid to Gas =

Sublimation

*When can sublimation occur?

Sublimation occurs in solids with vapor pressures that exceed atmospheric pressure at or near room temperature

*What is the relationship between the temperature in kelvins and the average kinetic energy of particles?

The Kelvin temperature of a substance is directly proportional to the average kinetic energy of the particles of the substance

*How are the conditions at which phases are in equilibrium represented on a phase diagram?

The conditions of pressure and temperate at which two phases exits in equalilbium are indicted on phase diagram by a line separated the phases

*How are the structure and properties of solids related?

The general properties of solids reflect the orderly arrangement and fixed locations of their particles.

What is the triple point of a substance?

The triple point represents the only conditions of temperature and pressure at which three phases of a substance can exits i equilibrium

*Under what conditions does boiling occur?

When a liquid is heated to a temperature at which particles throughout the liquid have enough kinetic energy to vaporize

-Phase diagram:

a graph showing the conditions at which a substance exists as a solid, liquid, or vapor

-Vapor pressure:

a measure of the force exerted by a gas above a liquid

-Vapor pressure:

a measure of the force exerted by a gas above a liquid in a sealed container; a dynamic equilibrium exists between the vapor and the liquid.

what type of solid has a relatively low melting point?

a molecular solid like sugar.

-Crystal:

a solid in which the atoms, ions, or molecules are arranged in an orderly, repeating, three-dimensional pattern called a crystal lattice -the shape of a crystal depends on the arrangement of the particles within it

-Vapor:

a substance that is normally a liquid at room temperature but the particles get enough kinetic energy to go into a gaseous phase

Standard temperature and pressure (STP) are defined as

a temperature of OC and a pressure of 101.3kPa or 1 atm

-Standard atmosphere(atm):

a unit of pressure; it is the pressure required to support 760 mmHG in a mercury barometer at 25C

The temperature 0 K, or −273.15°C, is called _______ zero. Theoretically, particles of matter at this temperature would have no ____________ ________.

absolute....kinetic energy

-Vaporization:

adding enough kinetic energy to enter the vapor phase

-Kinetic theory:

all matter consists of tiny particles that are in constant motion

two or more different molecular forms of the same element in the same physical state are called _____

allotropes

-Vacuum:

an empty space with no particles and no pressure

-Barometer:

an instrument used to measure atmospheric pressure

-Gas:

any substance normally found in the gas phase at room temperature

*what determines the shape of a crystal?

arrangement of the particles within the solid.

Why does boiling point decrease as altitude increases?

at high altitudes, atmospheric presser is lower than at sea level because boiling occurs when vapor pressure is equal to atmospheric press. a liquid boils at a lower temperature.

What kind of pressure is measured with a barometer?

atmospheric pressure

When the particles throughout a liquid have enough energy to vaporize _____ occurs

boiling

When a closed system has constant vapor pressure, a(n) ______ ________ exists between the liquid and its vapor

dynamic equilibrium

-heat:

energy that transfer between objects. It can only go one way(warmer———cooler: more genetic)(energy———less genetic energy) -The transfer will continue until you reach equilibrium

Volatile:

evaporates very quickly and easily

During _______, particles with enough energy escape at the surface of a liquid

evaporation

When vaporization occurs at the surface of a liquid that is not boiling, the process is called _________

evaporation

The boiling point of a liquid is the temperature at which the vapor pressies of the liquid is just equal to the _____ ____

external pressure

t/f: All the particles in a substance at a given temperature have the same kinetic energy.

false

t/f: after a liquid reaches it's boiling point, its temperature continues to rise until all the liquid vaporizes

false

t/f: The kinetic theory states that there are no attractions between the particles of a liquid.

flase

Simultaneous collisions of billions of particles in a gas with an object result in

gas pressure

When many particles in a gas simultaneously collide with an object, _______ _____ results

gas pressure

The arrangement and location of its particles affect the ________ ________ of a solid.

general properties

What force holds the particles of air in Earth's atmosphere?

gravity

-Ionic solids:

high melting points because relatively strong forces hold them together Ex: sodium chloride

Temperature on the _______ scale is directly proportional to the average kinetic energy of the particles of a substance.

kelvin

The _______ temp. of a substance is directly proportional to the average kinetic energy if the particles of the substance

kelvin

The ______ _____ makes three assumptions about the volume, the motion, and the collision of gas particles

kinetic theory

What theory explains the behavior of gases with respect to conditions such as temperature and pressure?

kinetic theory

What is an amorphous solid?

lacks an ordered internal structure

-Molecular solids:

low melting point Ex: hydrogen chloride Exceptions: wood and cane sugar decompose hone heated

-Temperature:

measure of the average amount of kinetic energy in a system

-Solids:

mostly crystalline

Do all solids melt when heated? explain?

no, some solids, like wood, decompose

Allotropes:

one of two or more different molecular forms of an element in the same physical state; oxygen(O2) and ozone(O3) are all allotropes of the element oxygen -Solid substances can exits in more than one form ex: carbon: diamond is a crystalline form of carbon. Graphite. buckminsterfullerene

A(n) ________ ________ relates the solid, liquid, and gas states of a substance to temperature and pressure.

phase diagram

The _____ of liquids depend on both the disruption of the particles in the liquid and the attraction between the particles

physical properties

-Crystal lattice:

repeating pattern of any one of four-teen kinds of unit cells

-Gas pressure:

results from the force exerted by a gas per unit surface area of an object. Gas pressure is the result of simultaneous collisions of billions of rapidly moving particles in a gas with an object.

-Gas pressure:

results from the forces exerted by a gas per unit surface area of an object

A crystalline solid has a certain arrangement of particles, which is reflected in its ______

shape

-Amorphous solid:

solid that lacks an ordered internal structure; denotes a random arrangement of atoms. Ex: rubber/plastic/asphalt

The process by which wet laundry dries on an outdoor clothesline in winter is called

sublimation

When the vapor pressure of a solid equals or exceeds atmospheric pressure at room temperature, ______ occurs.

sublimation

-Pascal(Pa):

the SI unit of pressure. Represents a very small amount if pressure. Normal atmospheric pressure: 100,000 Pa-100kilopascals (kPa)

-Normal boiling point:

the boiling point of a liquid at a pressure of 101.3 kPa or 1 atm

-Vaporization:

the conversion of a liquid to a gas or a vapor

-Vaporization:

the conversion of a liquid to a gas or vapor

-Kinetic energy:

the energy an object has because of its motion-temperature

A solid melts when...

the organization of its particles breaks down

As a liquid evaporates, why do only some of the particles break away from the surface of the liquid? Why does the liquid evaporate faster if the temperature is increased?

the particles throughout have different kinetic energy to overcome the attractive forces. As the temp. increases, the average kinetic energy increases and particles have enough kinetic energy t overcome the focus that are keeping them in the liquid state

-Triple point:

the point on a phase diagram that represents the only set of conditions at which all three phases exits in equilibrium with one another.

-Atmospheric pressure:

the pressure exerted by atoms and molecules in the atmosphere surrounding Earth, resulting from collisions of these particles with objects

Standard atmosphere (atm)

the pressure required to support 760mm of memory in a mercury barometer at 25 degrees celsius.

-Sublimation:

the process in which a solid changes to agas or vapor without passing through the liquid state. Ex: Iodine Applications: brewed coffee is frozen and the water vapor is removed with a vacuum pump, the rest is freeze-dried coffee.

-Unit cell:

the smallest group of particles within a crystal that retains the geometric shape of the crystal.

-Melting point(mp):

the temperate at which a substance changes from a solid to a liquid; the melting point of water of 0C

-Freezing point:

the temperature at which a liquid changes to a solid

-Boiling point(bp):

the temperature at which the vapor pressure of a liquid is just equal to the external pressure on the liquid

What happens to the temperature of a substance when the average kinetic energy of its particles increases?

the temperature of the substances increases

-Heat:

the transfer of energy from one object to another and the transfer happens from a direction of higher energy to lower energy

How are particles arranged in a crystal?

they are arranged in orderly 3-dimensional patterns

-Glass(super-cooled liquids):

transparent fusion product of inorganic materials that have called to a rigid state without crystallizing

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

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

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: tje temperature at which the liquid and solid states of a substance as in equilibrium is the same as the melting point and the freezing point of the substance

true

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: Some solid substances an exist in more than one form. Ex:

true. (allotropes)Carbon: graphite/diamond/buckminsterfullerene(?)

Gas pressure results from the force exerted by a gas per

unit surface area of an object

The conversion of a liquid to a gas or vapor is called ______

vaporization

-Evaporation:

vaporization that occurs at the surface of a liquid that is not boiling