learning intention understand that energy transfers in physical and chemical reactions occur all...

Learning Intention Understand that energy transfers in physical and

chemical reactions occur all around us. Energy transfers both explain natural phenomena and can be used for

practical applications.

Success Criteria1. I can …. describe how energy is associated with the motion of particles and relative position of the particles with in a molecule 2. I can … provide evidence for energy transformations3. I can … use a phase diagram to predict how changes in in external temperature and pressure affect the melting point and boiling point of a substance.

4. I can … explain the relationship between energy and heat5. I can … explain that energy is a quantitative property of a system that depends on the motion and interactions of matter within that system. 6. I can … calculate the heat transfer in chemical processes

What do States of Matter have to do with energy???

Nature of Gasses

• What does the word Kinetic refer to?

• Kinetic Theory– Gas particles have insignificant volume– No attractive or repulsive forces exist between the

molecules– Molecules are in constant Random Motion– All collisions are perfectly elastic

Pressure

Gas Pressure

• Force exerted by a gas per unit surface area• SI unit: pascal (Pa)

One standard atmosphere(atm) is the pressure required to support a column of mercury 760 mm high.

Write this down!!!1 atm = 760 mm Hg = 101.3kPa

Express the pressure 300 mmHg in kilopascals.

Express the pressure 300 mmHg in kilopascals.

101.3 kPa 760 mm Hg

Express the pressure 300 mmHg in kilopascals.

300 mm Hg 101.3 kPa = 39.99 kPa 760 mm Hg

Mercury Barometer

Kinetic Energy and Kelvin Temperature

• When substances are heated, the particles of that substance absorb energy. – The remaining energy speeds up the particles– Kinetic Energy: the energy of motion

↑ Temp = ↑ Kinetic Energy

Absolute Zero

• 0 Kelvin• The temperature at which the motion of

particles theoretically stops

• Has never been reproduced in a lab

Liquids• Ability to flow, but the particles are attracted

to each other by intermolecular forces.Vaporization: Liquid gas or vapor Evaporation: When vaporization occurs at the surface of a liquid

Vapor Pressure

• Force of gas above a liquid

Boiling Point• The temperature at which the vapor pressure

of a liquid is equal to the external pressure.– Bubbles of vapor form throughout the liquid

Nature of Solids

• Molecules tend to move slightly about a fixed point

• Packed in a highly organized manner• Melting Point: Temperature at which solids

turn into liquids

Changes of State

Phase Diagrams

Sublimation

• The change of state directly from a solid to a vapor.

In Class Activity

Understanding Phase Diagrams•Using a phase diagram, you can determine the changes in the ______ point and _____ point of a substance with changes in external _________ and ________.

In Class Activity

Understanding Phase Diagrams•Using a phase diagram, you can determine the changes in the melting point and boiling point of a substance with changes in external temperature and pressure.