chapter 10 states of matter. section 1: the kinetic-molecular theory of matter

Chapter 10States of Matter

Section 1: The Kinetic-Molecular

Theory of Matter

Standard 4.b.

Students know the random motion of molecules explains the diffusion of gases.

We will list the five assumptions of the kinetic-molecular theory of gases and describe the properties of gases.

Objectives

KMT

This is based on the idea that particles of matter are always in motion.

How it relates to gases: Ideal gas = a hypothetical gas that

perfectly fits all the assumptions of KMT. No ideal gas actually exists; but some do

come close.

5 Assumptions

Gases consist of large numbers of tiny particles that are far apart relative to their size.

Collisions between gas particles and between particles and container walls are elastic collisions (no net loss of total kinetic energy)

Gas particles are in continuous, rapid, random motion. Thus, they have kinetic energy.

5 Assumptions Cont.

There are no forces of attraction between gas particles. This is why they have no set shape

The temperature of the gas depends on the average kinetic energy of the particles of the gas.

Standard 4.b.

Students know the random motion of molecules explains the diffusion of gases.

We will list the five assumptions of the kinetic-molecular theory of gases and describe the properties of gases.

Objectives

Properties of Gases

No definite shapeNo definite volumeAbility to flow (fluid)Low density

Can be compressed smaller

DiffusionEffusion

Real Gases

A gas that does not behave completely according to the assumptions of KMT.

Noble gases and non-polar diatomic gases behave most like an ideal gas, as well as gases at high temperatures and low pressures.

Standard 4.b.

Students know the random motion of molecules explains the diffusion of gases.

We will list the five assumptions of the kinetic-molecular theory of gases and describe the properties of gases.

Objectives

Section 2 & 3:Liquids and Solids

Standard 4.a.

Students know the random motion of molecules and their collisions with a surface create the observable pressure on that surface.

We will describe the properties of liquids and discuss the processes of how liquids change.

We will describe the properties of solids and distinguish between the two types of solids.

Objectives

Properties of Liquids

No definite shapeHigher densityMostly incompressible

so definite volumeDiffusion

Surface tensionEvaporationBoilingCan form solids

Properties of Solids

Definite shapeDefinite volumeDefined melting

point

High densityIncompressibleLow rate of

diffusion

Types of Solids

Crystalline Solids: exist as single crystals or groups of crystals fused together. Ionic Crystals Covalent Network Crystals Metallic Crystals Covalent Molecular Crystals

Types of Solids

Amorphous Solids: are not arranged in a regular pattern. Glass and Plastic

Standard 4.a.

Students know the random motion of molecules and their collisions with a surface create the observable pressure on that surface.

We will describe the properties of liquids and discuss the processes of how liquids change.

We will describe the properties of solids and distinguish between the two types of solids.

Objectives

Chapter 10.4Changes of State

Standard 7.c.

Students know energy is released when a material condenses or freezes & is absorbed when a material evaporates or melts.

We will describe the processes that occur to cause a change of state.

We will interpret phase diagrams.

Objectives

Matter on earth can exist in any state—gas, liquid, or solid—and can change from one state to another.

Energy and Changes of State

When a substance changes from one state to another, energy is always involved.

The change will either be exothermic (releases heat) or endothermic (absorbs heat).

Changes of State

Change of State Process Example Endo or Exo?

SolidLiquid Melting IceWater

SolidGas Sublimation Dry IceCO2

LiquidSolid Freezing WaterIce

LiquidGas Vaporization WaterSteam

GasSolid Deposition SteamIce

GasLiquid Condensation SteamWater

Standard 7.c.

Students know energy is released when a material condenses or freezes & is absorbed when a material evaporates or melts.

We will describe the processes that occur to cause a change of state.

We will interpret phase diagrams.

Objectives

Phase Diagrams

Phase Diagram: a graph of pressure versus temperature that shows the conditions under which the phases of a substance exist. Tells you what state a substance will be in at

a certain temperature and pressure.

Triple point: the temperature and pressure conditions at which the three phases can coexist at equilibrium

Critical Point: the critical temperature and critical pressure of a substance.

Critical Temperature: the temperature above which the substance cannot exist as a liquid.

Critical Pressure: the lowest pressure at which the substance can exist as a liquid.

Name that state…

Temperature Pressure State

70°C 2.0 atm

100°C 0.5 atm

0°C 1.0 atm

Name that state…

Temperature Pressure State

70°C 2.0 atm

100°C 0.5 atm

0°C 1.0 atm

Liquid

Gas

Solid

Standard 7.c.

Students know energy is released when a material condenses or freezes & is absorbed when a material evaporates or melts.

We will describe the processes that occur to cause a change of state.

We will interpret phase diagrams.

Objectives

Homework

Pg 332 #2, 3Pg 336 #4, 5Pg 341 #2Pg 348 #6

Chapter 10.5Water

Standard 7.c.

Students know energy is released when a material condenses or freezes & is absorbed when a material evaporates or melts.

We will describe the structure of the water molecule and its properties.

We will calculate the amount of energy absorbed or released when water changes state.

Objectives

Structure of Water

Recall: Water has 2 Hydrogen and 1 Oxygen and has a bent structure.

Ice forms a hexagonal pattern Look at Fig 19 on pg 350 The empty spaces result in ices

low density and are why it floats.

Properties of Water

Pure water is transparent, odorless, tasteless and almost colorless. Any odor or taste is caused by impurities.

Water freezes and ice melts at 0°C and 1 atm. Molar enthalpy of fusion is 6.009 kJ/mol Water boils at 100°C and 1 atm. Molar enthalpy of vaporization is 40.79 kJ/mol

Going from ice to water requires energy. Going from water to ice releases energy. Going from water to steam requires energy. Going from steam to water releases energy. The amount of energy is the same, it is just

either required or released.

Standard 7.c.

Students know energy is released when a material condenses or freezes & is absorbed when a material evaporates or melts.

We will describe the structure of the water molecule and its properties.

We will calculate the amount of energy absorbed or released when water changes state.

Objectives

Calculating Amount of Energy

What quantity of energy is released when 804 g of water vapor condenses? Convert from grams to moles Multiply moles by 40.79 kJ/mol (Vaporization) Moles cancel out, units are kJ Answer = 1820 kJ

Calculating Mass from Energy

What mass of ice is required to release 2000 kJ of energy when melting? Divide kJ by 6.009 kJ/mol (fusion) kJ cancel out so you have moles. Convert moles to grams. Answer = 6000 g H2O

Standard 7.c.

Students know energy is released when a material condenses or freezes & is absorbed when a material evaporates or melts.

We will describe the structure of the water molecule and its properties.

We will calculate the amount of energy absorbed or released when water changes state.

Objectives

Homework

Pg 351 #4, 6 and practice problem #1, 2