Welcome to the States of Matter HMMM?

The Kinetic Molecular Theory Introduction to the Kinetic Molecular Theory

Gas particles are small, hard spheres with a small volume. 13.1 According to kinetic theory: Gas particles are small, hard spheres with a small volume. Gases are in constant, random, straight line motion Collisions are elastic

Kinetic Theory and a Model for Gases 13.1 Kinetic Theory and a Model for Gases Some Facts About Kinetic energy energy of motion ALL matter is in motion ALL matter has kinetic energy Higher temperature = more kinetic energy

(but not liquids or solids) Compressibility Cool Property of Gases (but not liquids or solids) Compressibility Measure of how much the volume of matter decreases under pressure. Large distance between gas molecules A crash dummy can be used to test the effectiveness of an air bag. Because gases can be compressed, the air bag absorbs some of the energy from the impact of a collision. Air bags work best when combined with seat belts.

Factors Affecting Gas Pressure Variables Related to Gases pressure (P) in kilopascals or atm volume (V) in liters or milliliters temperature (T) in kelvins (add to 273.15 to °C) the number of moles (n).

Common Pressure Conversions The SI unit of pressure is the pascal (Pa). Common Pressure Conversions 1atm = 101,325 Pa = 101.3 kPa = 760torr = 760 mmHg

Complete the following conversions 1.3 atm to KPa 789mmHg to atm 890.5torr to atm 2.5 atm to Pa and Kpa 670mmHg to torr

Introduction to the Gas Laws Boyles Law – pressure and volume Charles Law – temperature and volume Gay-Lussac’s – pressure and temperature

Boyle’s Law: Pressure and Volume If the pressure of a gas increases, the volume decreases. Indirect relationship

Factors Affecting Gas Pressure Volume If you… Decrease the volume(push down on the bike pump) Less room for the gas Hits the sides more often Increases the pressure

Factors Affecting Gas Pressure When the volume of the container is halved, the pressure the gas exerts is doubled. A piston can be used to force a gas in a cylinder into a smaller volume. When the volume is decreased, the pressure the gas exerts is increased. Interpreting Diagrams What happens to the gas pressure when the volume is reduced from 1 L to 0.5 L?

Click to Run Boyles Law Simulation

Charles’s Law: Temperature and Volume As the temperature of a gas increases, the volume increases. Direct Relationship

Charles’s Law: Temperature and Volume As the temperature of the water increases, the volume of the balloon increases. When the gas in the blue balloon is cooled at constant pressure, the volume of the gas decreases. When the gas is heated at constant pressure, the volume increases. Calculating What is the ratio of volume to temperature for each set of conditions? Round your answer to two significant figures.

Charles’s Law: Temperature and Volume Charles Law – Volume Temperature http://phet.colorado.edu/en/simulation/gas- properties

Gay-Lussac’s Law: Pressure and Temperature As the temperature of a gas increases, the pressure increases. Direct Relationship

Factors Affecting Gas Pressure Temperature If you… Increase the temperature Increases the kinetic energy Molecules move faster Hit the sides more often Increases the pressure

Gay-Lussac’s Law: Pressure and Temperature When a gas is heated at constant volume, the pressure increases. When a gas is heated at constant volume, the pressure increases. Interpreting Diagrams How can you tell from the drawings that there is a fixed amount of gas in the cylinders?

A Cool Model to Start Us Off http://www.harcourtschool.com/activity/states_of_matter/ More About States of Matter

What You Should Learn Recognize solids have stronger attractive forces than liquids and liquids have stronger forces than gases. Recognize solids have more ordered arrangement than liquids or gases. Explain why ionic solids melt at higher temperatures than covalent solids. Describe states of matter in terms of motion and arrangement of molecules or atoms.

Focus on Liquids

Fluid – any substance that flows 13.2 A Model for Liquids Fluid – any substance that flows Liquid Gas Both liquids and gases can flow. The liquid on the left is colored water. The gas on the right is bromine vapor. If a gas is denser than air, it can be poured from one container into another. These pictures were taken in a fume hood because bromine is both toxic and corrosive. Predicting Over time, what will happen to the gas in the uncovered beaker? Explain.

Stronger attractions than gases 13.2 A Model for Liquids Stronger attractions than gases Less space between molecules Denser than a gas

Model of a Liquid A quick Video

Orderly arrangement of atoms/molecules Fixed, vibrating in position 13.3 A Model for Solids Focus on Solids Orderly arrangement of atoms/molecules Fixed, vibrating in position

13.3 A Model for Solids The melting point (mp) is the temperature at which a solid changes into a liquid. A Video

Ionic Compounds Covalent Compounds Metal + Nonmetal Nonmetal + Nonmetal Very strong attractive forces Weak attractive forces Mostly solid at room temperature Mostly gases at room temperature High melting point Low melting point

A States of Matter Simulation