the kinetic molecular theory
DESCRIPTION
The Kinetic Molecular Theory. Movement in solids, liquids, and gases. The theory of moving molecules!. Describes the differences between gas, liquid, and solid states. Assumptions within the KMT. 1. Gases are made of tiny particles that are far apart from each other. - PowerPoint PPT PresentationTRANSCRIPT
The Kinetic Molecular
TheoryMovement in solids, liquids, and gases
The theory of moving molecules!
• Describes the differences between gas, liquid, and solid states.
Assumptions within the KMT
• 1. Gases are made of tiny particles that are far apart from each other.
• 2. Gas particles are in continuous, rapid, random motion
More Assumptions• 3. There are no attractive forces between
molecules under normal conditions.• 4. Collisions between particles are elastic (no
energy is lost due to friction).
Last Assumption• 5. Particles at the same temperature have the
same average kinetic energy.
States of Matter: a review
KMT & Changing State of Matter
• Gases- Attractions are insignificant
• Liquids- Attractions are more important, leading to a more ordered state
• Solids- Attractions are most important with a very ordered state!
KMT & Changing State
• Involves adding or removing energy (changing temperature) or changing pressure.
KMT & Changing States of Matter
• What happens, on a molecular level, when you add heat to a solid?o Molecules vibrate more rapidlyo Molecules “escape” to the liquid states and slide past each other.
• What happens when you boil/evaporate a liquid?o Molecules absorb more energy, move fastero Can break weak bonds that keep them liquid and “escape: into the gas
state.
KMT and Changing State of Matter
• The opposite occurs when you cool a gas down until it becomes a liquid and then cool the liquid until it solidifies.
What happens when we change pressure?
• Pressure – the force per unit area
• Volume- amount of space an object takes up• Temperature- average kinetic energy of the
particles• These 3 concepts are related to each other!
Pressure, Volume, & Temperature
• What would happen to the pressure from the molecules in the balloon if I decreased the volume?
Pressure & Volume• Decreasing the Volume would Increase the
Pressure
V P
• There is an inverse relationship between pressure and volume!
Volume & Temperature
• What would happen to the balloon if I increased the temperature?
Volume & Temperature
• Adding heat would increase the speed of the molecules, which increases the pressure inside the balloon, which increases the volume!