States of matter

🔬 Chapter 5: States of Matter 🔬

• Learning Outcomes 🎯:

  • State the basic assumptions of the kinetic theory as applied to an ideal gas.

  • Explain qualitatively in terms of intermolecular forces and molecular size, the conditions necessary for a gas to approach ideal behavior.

  • State and use the general gas equation pV = nRT in calculations.

  • Describe, using a kinetic-molecular model, the liquid state, melting, vaporization, and vapor pressure.

  • Describe in simple terms the lattice structures of crystalline solids, including ionic, simple molecular, giant molecular, hydrogen bonded, or metallic.

  • Discuss the finite nature of materials as a resource and the importance of recycling processes.

  • Outline the importance of hydrogen bonding to the physical properties of substances, including ice and water.

• Recycling Materials ♻️:

  • Recycling metals saves energy, conserves supplies of the ore, reduces waste, and is often cheaper than extracting metals from their ores.

  • Recycling copper is important due to the low percentage of copper in most remaining ores and the energy savings in recycling compared to extraction.

  • Recycling aluminum is much cheaper than extracting it from bauxite ore, and there is a 95% saving in energy by recycling aluminum compared to extracting it from its ore.

• The Gaseous State 💨:

  • The kinetic theory of gases assumes that gas molecules move rapidly and randomly, the distance between gas molecules is much greater than the diameter of the molecules, there are no forces of attraction or repulsion between the molecules, and all collisions between particles are elastic.

• The Liquid State 💧:

  • When a solid is heated, the energy transferred makes the particles vibrate more vigorously, the forces of attraction between the particles weaken, and the solid changes to a liquid (melting).

  • In a liquid, particles are close together but have enough kinetic energy to slide past each other.

  • Vaporization is the change from the liquid state to the gas state, and the energy required for this change is called the enthalpy change of vaporization.

• The Solid State 🧱:

  • Solids have fixed shape and volume, with particles touching each other and usually arranged in a regular pattern.

  • The state of a substance at room temperature and pressure depends on its structure and bonding, including simple atomic, simple molecular, giant ionic, giant metallic, and giant molecular structures.