CHAPTER 3States of Matter

5 STATES OF MATTER

Solid Liquid Gas Plasma Bose-Einstein condensate

SOLIDS

What makes a solid a solid?

Definite shape and volume The atoms are packed close

together They have an orderly

arrangement Particles vibrate but don’t move

LIQUIDS

What makes a liquid a liquid?

Definite volume Takes the shape of container Flows easily Loosely held together Arrangement more random

GASES

What makes a gas a gas?

Not definite shape nor volume No pattern to them Lots of space between, no bonds Can be compressed (aerosol

cans)

PLASMAS

Exists at extremely high temperatures

Very similar to gases but the atoms have lost electrons, we call them free electrons

Most common state in the universe

BOSE-EINSTEIN CONDENSATE

Exists at extremely low temperatures

Named after the two scientists S. Bose and A. Einstein

Near -273 oC groups of atoms behave as one

KINETIC ENERGY

Kinetic energy is the energy of movement

The faster an object moves, the more Kinetic Energy it has

Even though we may not see it, all particles are constantly moving. This is the Kinetic Theory of matter.

HOW THE DIFFERENT PARTICLES MOVE Gas: Particles are always

bouncing around, colliding into each other

They move in a straight line. If they collide one atom may slow down and the other may speed up.

The particles in a gas have weak attractions and don’t have an affect on movement.

KINETIC THEORY OF GASES

The constant motion of particles in a gas allows a gas to fill a container of any shape or size

We just looked at the 3 main points of this theory on the previous slide

BEHAVIOR OF LIQUIDS

Has a definite volume because it is heavier and their attraction to each other.

Liquids are closely packed like a hallway

Particles in a liquid can flow to new locations because the attraction keeps the particles close together

BEHAVIOR OF SOLIDS

Particles have a fixed locations and volume doesn’t change

They vibrate but never leave their location

PHASE CHANGES

The reversible physical change that occurs when substance changes from one state of matter to another.

The temperature during a phase change stays the same.

Energy is either absorbed or released during a phase change

EXOTHERMIC VS. ENDOTHERMIC Endothermic: Absorbs energy

from its surroundings– Types: Melting, Vaporization,

Sublimation

Exothermic: Releases energy to its surroundings– Types: Freezing, Condensation,

Deposition

THE CYCLE

PRESSURE

Pressure is the result of a force distributed over an area.

SI unit for Pressure based on Force and area

Force is measure in newtons (N) Area is measure in meters2

Pressure is N/m2

Can be expressed as a Pascal (Pa): SI Unit

GAS PRESSURE

Collisions between particles and the walls cause the pressure in a close container.

Factors that affect gas Pressure– Temperature: High Temp=High

KE=More collisions=Greater pressure

– Volume: Reducing Volume=Greater pressure

– Number of Particles: Increase #= Greater pressure

GAS LAWS

Formulas that explain the behaviors of gases at different temperatures, pressures, and volumes.

CHARLES’S LAW

States that the volume of a gas is directly proportional to its temperature in Kelvins if the pressure and the number of particles of the gas are constant.

What that means: If you increase the temperature you increase the volume

CHARLES’S LAW FORMULA

V1 = V2T1 T2

Example Problems

BOYLE’S LAW

Shows relationship between pressure and volume of a gas

It can be described as an inverse relationship

As pressure increases, volume would decrease and vice-versa

BOYLE’S LAW FORMULA

P1V1 = P2V2

Example Problems

COMBINED GAS LAW

Shows the total relationship between temperature (in Kelvins), volume, and pressure of a gas when particles are constant.

P1V1 = P2V2 T1T2

Example Problems

CHARLES’ LAW EXAMPLES

What volume will a sample of hydrogen occupy at 28.0 oC if the gas occupies a volume of 2.23 L at a temperature of 0.0 oC?   Assume that the pressure remains constant.

If a gas occupies 733 mL at 10.0 oC, at what temperature will it occupy 950 mL?  Assume that pressure remains constant.

A gas occupies 560 mL at 285 K.  To what temperature must the gas be lowered to, if it is to occupy 25.0 mL?  Assume a constant pressure.

What volume would a sample of helium occupy at standard temperature, if it occupies 250 cm3 at 185 K?  Assume constant pressure.

A sample of oxygen gas has a volume of 2.73 L at 21.0 oC.  At what temperature would the gas have a volume of 4.00 L?

BOYLE’S LAW

The volume of the lungs is measured by the volume of air inhaled or exhaled.  If the volume of the lungs is 2.400 L during exhalation and the pressure is 101.70 kPa, and the pressure during inhalation is 101.01 kPa, what is the volume of the lungs during inhalation? 

It is hard to begin inflating a balloon.  A pressure of 800.0 kPa is required to initially inflate the balloon 225.0 mL.  What is the final pressure when the balloon has reached it's capacity of 1.2 L?

If a gas at 25.0 °C occupies 3.60 liters at a pressure of 1.00 atm, what will be its volume at a pressure of 2.50 atm?

A gas occupies 12.3 liters at a pressure of 40.0 mm Hg. What is the volume when the pressure is increased to 60.0 mm Hg?

A gas occupies 1.56 L at 1.00 atm. What will be the volume of this gas if the pressure becomes 3.00 atm?

COMBINED GAS LAW EXAMPLES 500.0 liters of a gas are prepared

at 10 atm and 200.0 °C. The gas is placed into a tank under high pressure. When the tank cools to 20.0 °C, the pressure of the gas is 30.0 atm. What is the volume of the gas?

What is the volume of gas at 2.00 atm and 200.0 K if its original volume was 300.0 L at 0.250 atm and 400.0 K?

A gas balloon has a volume of 106.0 liters when the temperature is 45.0 °C and the pressure is 740.0 mm of mercury. What will its volume be at 20.0 °C and 780 .0 mm of mercury pressure?

A gas is heated from 263.0 K to 298.0 K and the volume is increased from 24.0 liters to 35.0 liters by moving a large piston within a cylinder. If the original pressure was 1.00 atm, what would the final pressure be?

73.0 mL of nitrogen at STP is heated to 80.0 °C and the volume increase to 4530 mL. What is the new pressure?