# states_of_matter.ppt

21 Apr 2023
1 sur 29

### states_of_matter.ppt

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• 3. 3 Upon completion of this course, the students should able to:  Demonstrate basic knowledge of basic concepts of physical pharmaceutical principles essential for their pharmacy study in the next years.  Demonstrate basic knowledge of important pharmacy-related physical principles in areas such as states of matter, phase equilibrium and phase rule, solutions of non-electrolytes, adsorption, solubility, buffers and isotonic solutions and rheology. The course also presents basic understanding of types of disperse systems and methods of their preparation and assessment.
• 5. STATES OF MATTER •The Four States of Matter • Four States • Solid • Liquid • Gas • Plasma
• 6. STATES OF MATTER Based upon particle arrangement Based upon energy of particles Based upon distance between particles
• 7. STATES OF MATTER SOLIDS •Particles of solids are tightly packed, vibrating about a fixed position. •Solids have a definite shape and a definite volume.
• 8. The molecules of solid are locked in a rigid structure and can only vibrate. (Add thermal energy and the vibrations increase.) Some solids are crystalline, like table salt, in which the atoms are arranged in a repeating pattern. Some solids are amorphous, like glass, in which the atoms have no orderly arrangement. Either way, a solid has definite volume and shape. SOLIDS
• 9. STATES OF MATTER LIQUID  Particles of liquids are tightly packed, but are far enough apart to slide over one another.  Liquids have an indefinite shape and a definite volume.
• 10. A liquid is virtually incompressible and has definite volume but no definite shape, if you pour a liter of juice into several glasses, the shape of the juice has changed but the total volume hasn’t. LIQUID
• 11. STATES OF MATTER GAS  Particles of gases are very far apart and move freely.  Gases have an indefinite shape and an indefinite volume.  If a container of CO2 is opened, it will diffuse throughout the room.
• 12. PHASE CHANGES Description of Phase Change Term for Phase Change Heat Movement During Phase Change Solid to liquid Melting Heat goes into the solid as it melts. Liquid to solid Freezing Heat leaves the liquid as it freezes.
• 13. PHASE CHANGES Description of Phase Change Term for Phase Change Heat Movement During Phase Change Liquid to gas Vaporization, Heat goes into the liquid as it vaporizes. Gas to liquid Condensation Heat leaves the gas as it condenses. Solid to gas Sublimation Heat goes into the solid as it sublimates.
• 15. But what happens if you raise the temperature to super-high levels… between 1000°C and 1,000,000,000°C ? Will everything just be a gas?
• 16. STATES OF MATTER PLASMA  A plasma is an ionized gas.  A plasma is a very good conductor of electricity and is affected by magnetic fields.  Plasmas, like gases have an indefinite shape and an indefinite volume. • Plasma is the common state of matter in the universe, since the insides of stars are plasmas.
• 17. STATES OF MATTER SOLID LIQUID GAS PLASMA Tightly packed, in a regular pattern Vibrate, but do not move from place to place Close together with no regular arrangement. Vibrate, move about, and slide Well separated with no regular arrangement. Vibrate and move freely at high Has no definite volume or shape and is composed of electrical charged particles
• 18. The term fluid refers to gases and liquids. Gases and liquids have more in common with each other than they do with solids, since gases and liquids both have particles that are free to move around. They are not locked in place as they are in a solid. The hotter the fluid, the faster its molecules move, and the more space the fluid will occupy. Also, unlike solids, fluids can flow. Fluids
• 19. Does Heat Affect Matter?
• 20. Fast Facts about Heat The boiling point: is the temperature at which a substance changes from a liquid to a gas. How does the movement of the particles change as it nears the boiling point? The particle move faster and faster until they escape from the liquid.
• 21. Fast Facts about Heat The freezing point: is the temperature at which a substance changes from a liquid to a solid. How does this happen? The particles move slower until they are closer together.
• 22. Pressure & Freezing For most liquids the freezing point increases if its pressure is increased, i.e., it’s easier to freeze most liquids if they’re subjected to high pressures. In order to turn a liquids into a solid, the molecules typically must get close enough together to form a crystal. Low temps mean slow moving molecules that are closer together, but high pressure can squeeze the molecules closer together, even if they’re not moving very slowly.
• 23. Water is an exception to this because, due to its molecular shape, it expands upon freezing. So, squeezing water makes freezing it harder. The pressure on ice due to a passing skater can actually melt a small amount of the ice. Pressure & Freezing
• 24. Pressure & Boiling The lower the pressure on a liquid, the easier it is to make it boil, i.e., as pressure increases, so does the boiling pt. This is because in order for a liquid to boil, molecules need enough kinetic energy to break free from the attraction of the molecules around it. It’s harder for a liquid to vaporize when subjected to high pressure, since gases take up more space than liquids.
• 25. Water, for example, boils at temps below 100 ºC up in the mountains where the air pressure is lower. It takes longer to cook food in boiling water at high altitudes because the boiling water isn’t as hot. In a vacuum water will boil at any temp, since there is no pressure at the surface to prevent the water from vaporizing. At high pressure water boils at a high temp. In a pressure cooker water can remain liquid up to 120 ºC, and the hotter water can cook food faster. Pressure & Boiling
• 26. Freezing of Solutions The freezing point of a solution, such as salt water, is lower than the freezing point for the solvent by itself, e.g., pure water. The higher the concentration of the solute, e.g. salt, the more the freezing point is lowered. The reason it is more difficult to freeze a liquid when a substance is dissolved in it is because the “foreign” molecules or atoms of a solute interfere with the molecules of the solvent as they’re trying to form a crystalline structure.
• 27. Boiling and Evaporation Evaporation takes place only at the surface of a liquid or solid, while boiling takes place throughout the body of a liquid. Boiling occurs at the boiling temperature. Particles that have “higher kinetic energy” escape and become vapor (gas).
• 28. Factors affecting the rate of evaporation: