Good Morning! 1/18/2016 Today we will… –Be working through the notes for Chapter 10. –The Chapter 10 Packet is going to be due on Monday, not Friday as the schedule suggests. –We have Advisory today, the 25 minute variety –We will be working on the notes in groups on the Laptops. Explanation will be on the next slide

To Access the Powerpoint… Log on first (the laptops must be connected to the internet) Then open the Folder names “Shortcut to Science Shares” In this folder open up “Durand” Then Chem then States of Mater. Finally click on the ppt named Ch 10 notes.

Chapter 10 Notes Necessary Assumptions of Kinetic Theory

Gases are composed of particles that are very small, hard spheres that are relatively far apart.

There is lots of empty space between the gas particles.

There is no significant attractive or repulsive force between the gas particles.

The gas particles move rapidly in constant random motion in a straight line. This is called a random walk.

Gas particles only change direction if they collide with another gas particle or the wall of the container.

All collisions are perfectly elastic. In other words, kinetic energy is transferred without any loss in the collision.

Uncontained gases can diffuse into space without limit. Link to Video

Diffusion: describes the mixing of gases. The rate of diffusion is the rate of gas mixing. Diffusion

Pressure is equal to force/unit area SI units = Newton/meter 2 = 1 Pascal (Pa)

1 standard atmosphere = kPa 1 standard atmosphere = 1 atm = 760 mm Hg = 760 torr

Measuring Pressure The first device for measuring atmospheric pressure was developed by Evangelista Torricelli during the 17 th century. The device was called a “barometer” Baro = weight Meter = measure

An Early Barometer

The Aneroid Barometer

Standard Temperature and Pressure“STP” Standard Temperature and Pressure “STP” P = 1 atmosphere, 760 torr T =  C, 273 Kelvins The molar volume of an ideal gas is liters at STP

Converting Pressure Units. 1 atmosphere (Atm) = 760 mm Hg (Torr) = kiloPascals(kPa) Convert 2.5 atm to kPa 2.5 atm x kPa 1 atm = kPa

Vaporization : Changing state from a liquid to a gas phase by heating.

Evaporation :When vaporization occurs at any temperature.  Only occurs at the surface of a liquid.

Triple Point :The conditions necessary for a substance to be in equilibrium with all its phases. (Solid, Liquid, Gas) All phases exist at the same time!  Liquid  gas =gas  liquid  Solid  liquid =liquid  solid  Solid  gas=gas  solid

Phase changes by Name

Sublimation :Occurs when a solid changes directly to a gas phase without passing through the liquid state.  Example: (Dry Ice)

Sublimation happens to solids that have high vapor pressure.

Phase changes by Name

Carbon dioxide CarbonCarbonCarbonCarbon dioxidedioxidedioxidedioxide

Water WaterWaterWaterWater

Carbon CarbonCarbonCarbonCarbon

Kinetic Theory and Solids  Motion is vibration or rotation of atoms around a fixed point.

Solid: Have a fixed mass and volume. True Solid : A substance that has a fixed melting point.

Amorphous Solid : Disordered arrangement of the particles resulting in a solid that has no definite melting point.  Glass is an amorphous solid. (Has a very high viscosity)

Types of Solids Amorphous solids: considerable disorder in their structures (glass).

Resistance to flow (molecules with large intermolecular forces). Viscosity

Representation of Components in a Crystalline Solid The spheres represent atoms, ions, or molecules that make up the substance. Lattice: A 3-dimensional system of points designating the centers of components

Unit Cell :Smallest group of atoms that can make a geometric arrangement.

Simple-cubic

Body-centered

Face-centered

Allotropes : Different molecular forms of the same element in the same physical state. Graphite Diamond