1 / 14

Phase/State Changes

Phase/State Changes. A Second Look. Changes of State. Change of a substance from one physical form to another. All state changes are PHYSICAL CHANGES A change of state requires a loss or gain of energy by a substance’s particles. To change States you must add or lose ENERGY!.

maxim
Download Presentation

Phase/State Changes

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Phase/State Changes A Second Look

  2. Changes of State • Change of a substance from one physical form to another. • All state changes are PHYSICAL CHANGES • A change of state requires a loss or gain of energy by a substance’s particles. • To change States you must add or lose ENERGY!

  3. What Causes Change of State? • Adding or taking away energy (heat!)

  4. Freezing – Liquid to Solid • Freezing is the change of state from a liquid to a solid. • The temperature at which a liquid changes into a solid is the liquid’s freezing point. • For a liquid to freeze, energy must be removed from the liquid to slow the movement of the particles.

  5. Melting Point – Solid to Liquid • Meltingis the change of state from a Solid to a Liquid. • The temperature at which a solid changes into a liquid is the solid’s Melting point. • For a solid to melt, energy must be added to the solid to speed up the movement of the particles. • Since melting is the opposite of freezing, they happen at the same temperature. Liquid water freezes at the same temperature as ice melts 0 degrees Celcius.

  6. Vaporization- Liquid to Gas • Evaporation is the change of state from a liquid to a gas on the surface of the liquid. It does not require a temperature change. • Boiling is the change of a liquid to a vapor, or gas. The temperature at which this change happens is the boiling point. • Boiling is different from evaporation because boiling happens throughout the whole liquid, evaporation just happens on the surface of the liquid. • Boiling and evaporation are similar because they both change a liquid to a gas (Vaporization)

  7. Effects of Pressure on Boiling Point • Atmospheric Pressure changes depending on where you are in relation to sea level. • Pressure is lower at higher elevation. The higher you are the fewer air particles are above you. So the pressure is lower. • In Denver water boils at 96 degrees C. • In Perris water boils at 100 degrees C.

  8. Condensation – Gas to Liquid Condensation is the change of state from a gas to a liquid. Condensation and evaporation are the reverse of each other. The condensation point is the temperature at which a gas becomes a liquid. For condensation to occur, energy must be removed from the gas to slow the movement of the particles.

  9. Sublimation – Solid to Gas • Sublimation is the change of state in which a solid changes directly to a gas. • In sublimation, the particles must go from being very tightly packed to being spread far apart. • For sublimation to occur, the solid must gain energy for the particles to overcome their attractions.

  10. Temperature and Changes of State • When temperature changes, the speed of the particles also changes • But when changes of state happen, the temperature of the substance doesn’t raise or lower until the change is complete. • Continued heating of a liquid at its boiling point will change the liquid entirely until it is all evaporated. The temperature of water cannot go higher than 100 degrees C until all the liquid water is turned to gas.

More Related