State of Matter Changes
We know that we can change matter from one state to another. What are those state of matter changes called? Solid Liquid Gas and Plasma
Solid Liquid Gas add energy sublimation evaporation melting vaporization Solid Liquid Gas freezing condensation lose energy
Phase Diagram of Water
Definitions for FLASHCARDS The process of turning a liquid to a gas BEFORE the boiling point. Happens at the surface! = evaporation Gaining energy
Definitions for FLASHCARDS The process of turning a liquid to a gas AT the boiling point. Happens throughout substance! = vaporization Gaining energy
Definitions for FLASHCARDS The process of turning a liquid to a solid. = freezing Losing energy
Definitions for FLASHCARDS The process of turning a gas to a liquid. = condensation Losing energy
Definitions for FLASHCARDS The process of turning a solid to a liquid. = melting Gaining energy
Definitions for FLASHCARDS The process of turning a solid to a gas. = sublimation Gaining energy
Phase Diagram of Water Why is the plateau at section “B” much longer than at section “A”? B A
Phase Diagram for Water The “flat lines” or plateaus on the graph show that even though the substance is continuing to be heated there is no change in temperature. If we are reading the graph to the right, the energy is going to the weakening or breaking of bonds. If we are reading the graph to the left, the energy is going to the rebuilding or strengthening of bonds.
Phase Diagram for Water Bonds are breaking or reforming Bonds are weakening or strengthening
Phase Diagram for Water *Why is the plateau from liquid to gas so much longer than the plateau from solid to liquid? It takes a lot more energy to make or break/reform bonds than it does to weaken or strengthen them!!!
Phase Diagram for Water A phase diagram can be used to identify a substance by its plateaus!!! What key physical properties do the plateaus tell us?!?! Melting pts. and Boiling pts.!!!
Find the Melting and Boiling Points =90 oC =55 oC B.P. M.P.
Identifying a Substance Lets say you come across an unknown solid substance… one way to identify it is to apply heat and graph its phase diagram… Phase Diagram…
Now let’s put it all together… If you combine what you know about the individual states of matter with what you know about state changes… you can come up with a definition that explains what is going on at the molecular level of a state change. Challenge: Write the molecular definition for each state change.
Definitions for FLASHCARDS Molecules which have been rigid gain energy to move freely and escape the bonds. = sublimation (molecular) Gaining energy
Definitions for FLASHCARDS Rapidly moving molecules gain energy which allows them to escape the bonds between them at the boiling point. = vaporization (molecular) Gaining energy
Definitions for FLASHCARDS Rapidly moving molecules gain energy below the boiling point which allows them to escape the bonds. = evaporation (molecular) Gaining energy
Definitions for FLASHCARDS Molecules which have been rigid gain energy to move freely, but are not able to escape the bonds. = melting (molecular) Gaining energy
Definitions for FLASHCARDS Rapidly moving molecules lose energy and can no longer resist the bonds, but are still able to move freely. = condensation (molecular) Losing energy
Definitions for FLASHCARDS Molecules which have been moving freely but not able to escape the bonds, lose energy and vibrate in place. = freezing (molecular) Losing energy
Which phase change(s) gain or absorb energy? Vaporization Evaporation Melting Sublimation Which phase change(s) lose or release energy? Condensation Freezing
Putting it all together now! Label all the different sections with the correct phase change. Condensation . Liquid Gas F Freeze Vaporization Evaporation . Solid Boiling Point Liquid G (Bonds are Breaking/ reforming) Melting Point Melting (Bonds are weakening strengthening) Solid