Zusammenfassung der Ressource
Kinetic Model of Matter
- all matter is made of tiny particles in motion
- Brownian motion
- refers to irregular motion of smoke in air or pollen in water
- Einstein explanation for the motion as
caused by bombardment of air particles.
- Bigger visible particles are under continuous bombardment by smaller
invisible particles and are kept in continuous random motion
- Kinetic model of matter
- kinetic ==> moving
- States that all matter is made of tiny particles in continuous motion
- Comparing different states of matter
- Solid
- Physical properties: Incompressible,
fixed shape and volume
- Molecules are packed closely
- Strong intermolecular force
- Motion of particles: Vibrate about fixed
positions
- Liquid
- Incompressible,
fixed volume, takes
shape of vessel
- Packed closely
- Some attractive forces
- Free to move within vessel
- Gas
- Compressible,
no fixed shape or
volume
- Far apart
- Little attractive forces
- Free to move at high speeds
- Temperature of matter is related to kinetic
enegy possessed by the particles
- In ascending order, solids, liquids, gases
- Note: phase change is related to potential energy
- In general, matter in solid state
have the least spacing, followed
by liquid and gas.
- Exception: Water has a greater
spacing in solid than in liquid state,
minimum spacing at 4 degree celcius
- Gas Laws
- Boyle's
- p is inversely
proportionate to V,
p1V1=p2V2
- Explained using KMM: For gas compressed slowly (same temperature), the
frequency of the gas particles bouncing off the surface of the vessel increases
due to reduced volume, causing an increase in pressure in gas
- T is the constant
- Charles's
- V is proportionate to T
- For gas in an insulated (temperature allowed to increase) vessel with a frictionless (same
pressure) piston, temperature increase results in the average speed of particles to increase,
which will increase force of collision on the piston, pushing the piston outwards until gas
pressure is the smae as pressure in the surroundings.
- p is the constant
- Gay-Lussac's
- p is proportionate to T
- For gas kept in an insulated vessel (same volume) temperature increase results in the average
speed of particles to increase. This in turn increases both the frequency of the gas particles
bouncing off the surface, and the force of collisions, causing an increase in pressure of gas.
- V is the constant
- Summary
- Brownian motion demonstrates moving
nature of gas/liquid particles.
- Kinetic model: particles are in constant motion, temperature
of substance is related to motion of particles
- Gas laws: relationship
between p, V and T