Chem States of Matter

Kinetic Theory of Matter

all matter made of Particles that are always in motion

What are ideal gases?

A hypothetical gas that perfectly fits all the assumptions of the kinetic-molecular theory

What are the assumptions of ideal gases?

1. the gas particles have negligible volume compared to the container volume,

2. there are no intermolecular forces between particles,

3. all collisions between particles are perfectly elastic (no energy loss)

4. the gas particles are in constant random motion

sublimation/deposition point

temperature when vapor pressure=total applied pressure

Boiling

liquid transforms into a gas when heated to its "boiling point,"

• which occurs when the vapor pressure exerted by the liquid molecules becomes equal to the surrounding atmospheric pressure, causing bubbles of vapor to form within the liquid and rise to the surface, essentially escaping as gas

Melting

the process where a solid substance transforms into a liquid by absorbing heat, causing its molecules to gain enough energy to overcome the forces holding them together in a fixed structure, allowing them to move more freely and slide past each other as a liquid

What are the properties of actual gases?

• no fixed shape or volume,

• low density,

• high compressibility,

• ability to diffuse rapidly,

• exerting pressure

• experience intermolecular forces (attraction and repulsion between molecules)

Most gases behave ______________ if pressure is not very high and temperature is not very low

nearly ideally

Both gases and liquids are considered...

fluids

Real gases

Gases that do not behave completely according to the assumptions of the kinetic-molecular theory (This means noble gases behave the closest to ideal gases because the particles have little attraction for each other)

At high pressure and low temperatures, gas particles will be...

closer together and their kinetic energy will be insufficient to overcome the attractive forces

The more polar a molecule, the _________ the attractive forces between them, and the more they deviate from ideal behavior

greater

Structure of solids

• particles closely packed

• volume and shape fixed

• not compressible/expandable

• no particle flow

In liquids diffusion occurs...

more rapidly as temperature increases

Sublimation

absorbing enough energy to overcome the intermolecular forces holding its particles together

Vaporization

The process by which a liquid or solid changes to a gas

Evaporization

The process by which particles escape from the surface of a nonboiling liquid and enter the gas state

Dynamic equillibrium

• balance of changes ( vaporization and condensation)

Freezing Point

avg kinetic energy when liquid cools and particles don’t have enough kinertic energy to overcome interparticle forces

• particles give up more energy, frozen, avg kinetic energy gets fixed

Two types of solids

Crystalline and amorphous

exothermic changes

• energy given off during formation of new bonds

• liquid to solid (freezing)

• gas to liquid (condensation)

• gas to solid (depostion)

endothermic changes

• energy supplied to break bonds

• solid to liquid (melting)

• liquid to gas (vaporization)

• solid to gas (sublimation)

capillary rise/cappillarity

when adhesive forces pull fluid upward until downward force of gravity counters the net pull (plants)

-capillary

tube of small diameter

adhesion

attraction bw diff materials

Surfactant

surface tension disrupted by adding surface active agent (detergent, soap)

Crystalline solids

Solids that are arranged in an orderly geometric repeating pattern called crystals

Four types of crystalline solids

1. Ionic

2. molecular

3. metals

4. covalent network

Surface Tension

tendency of liquid surfaces at rest to shrink into the minimum surface area possible.

Viscosity

measure of resistance to flowing of particles in liquid

higher when higher attractive forces and slower liquid flow and higher temperature

Properties of Liquids

• interact strongly

• particles closely packed

• sufficient average kinetic energy to overcome some but not all interparticle forces

• shape depends on container

• not compressable

• able to flow

• not expandable

• denser than gas and diffuse slower

Amorphous solid

Solids where the particles are arranged randomly

Diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration

Effusion

A process by which gas particles pass through a tiny opening

Fluid

A substance that can flow and therefore takes the shape of its container

Volume and Pressure

inverse relationship

Temperature and Volume

direct proportion

Temperature and Pressure

direct proportion

moles and volume

direct realtionship

moles and pressure

direct proportion

moles and temperature

inverse relationship

molecular

Basic Unit: molecules

interparticle forces: varies

MP&BP: low to medium b/c weak intermolecule forces need to be broken not covalent

Solubility: like dissolves like

electric conductivity: not very conductive (separate into neutral molecules when molten/dissolved)

ionic solids

Basic Unit: cations & anions

interparticle forces: ionic bond

MP&BP: very high

Solubility: dissolve only in very polar solvent (H20)

electric conductivity: conduct in aqueos and molten

metal solids

Basic Unit: nuetral atoms (metal cores & free electrons)

interparticle forces: metallic bond

MP&BP: medium to very high

Solubility: insoluble

electric conductivity: conducts well as solids and liquids

covalent network

Basic Unit: atoms

interparticle forces: covalent bonds

MP&BP: very high

Solubility: insoluble

electric conductivity: none to poor

Alloys

• mixture in which majority component is solid

• w/ point deflects

Point deflects

• vacancy: absence of atom/ion

• substitiutional: minority atoms take places of majority atoms if similar in size

• interisitial: minority atoms fit between majority atoms

Crystal Systems

• cubic

• tetragonal:

• orthorhombic

• monoclinic

• triclinic

• hexagonal

• rhombohedral

Cubic system

simple cubic

body centered cubic

face centered cubic

polymorphism

materials existing in multiple crystalline forms ( carbon)

Allotropes

2 or more forms of same element in same physical state