Kinetic Particle Theory Flashcards
what does the Kinetic Particle Theory state? (3 points)
1) all matter made up of tiny, discrete particles
2) particles in constant random motion and move at different speeds in solids/liquids/gases
3) there are spaces between particles of matter, different between solids/liquids/gases
what are 6 things to take note of when drawing particles?
1) size of particles same even in different states
2) no need to fill all the space provided; should have enough particles to illustrate concept
3) particles cannot overlap
4) spaces between particles in liquid state should not be able to fit another particle
5) particles to be drawn at the bottom of box
6) closely packed implies that particles touch one another
what are the different arrangement of particles in solids, liquids and gases?
solid: very closely packed together in an orderly arrangement
liquid: closely packed together in a disorderly arrangement
gas: very far apart in a disorderly arrangement
what are the differences in the movement of particles in solids, liquids and gases?
solid: vibrate about their fixed positions
liquid: move freely throughout liquid
gas: move freely and randomly at high speed
what are the differences in the KE of particles in solids, liquids and gases?
solid: high
liquid: higher
gas: highest
what are the differences in attractive forces between particles of solids, liquids and gases?
solid: strongest
liquid: strong
gas: weak
what are the differences in volumes and shapes of solids, liquids and gases?
VOLUME
solid: fixed
liquid: fixed
gas: not fixed
SHAPE
solid: fixed
liquid: not fixed
gas: not fixed
what are the differences in flow of particles of solids, liquids and gases?
solid: cannot flow
liquid: flows easily
gas: flows in all directions
what is melting?
change of state of substance from solid to liquid state
what is melting point?
temperature at which solid changes into liquid
what happens during melting?
when solid heated, particles gain thermal energy and vibrate faster
as the temperature increases, particles gain enough energy to overcome the strong forces of attraction holding them in their fixed positions
particles can now move freely throughout liquid
why does the temperature remain constant during the melting process?
all the thermal energy taken in by the particles is used to overcome the forces of attraction holding the particles in their fixed positions
what is freezing?
change of state of substance from liquid to solid state
what is freezing point?
temperature at which liquid changes into solid
what happens during freezing?
particles lose kinetic energy and move more slowly
when the temperature is low enough, particles will no longer have enough energy to move freely and start settling into fixed positions as stronger forces of attraction form between them
particles can now only vibrate about in their fixed positions
why does the temperature remain constant during the freezing process?
thermal energy is released as particles of the liquid are attracted to one another to form a solid
this energy is given out to the surroundings
what is boiling?
change of state of substance from liquid to gaseous state
what is boiling point?
temperature at which liquid changes into gas
what happens during boiling?
when liquid heated, particles gain thermal energy and move faster
as the temperature increases, particles in liquid gain enough energy to overcome the forces of attraction holding them together
particles are now far apart and can move freely in all directions at high speed
why does the temperature remain constant during the boiling process?
all the thermal energy taken in by the particles is used to overcome forces of attraction between particles in liquid state
what is evaporation?
process in which a liquid turns into gas at a temperature below its boiling point
what are 4 differences between evaporation and boiling?
evaporation:
1) occurs only at surface of liquid
2) occurs at any temp. below boiling point
3) slow process
4) no bubbles formed
boiling:
1) occurs throughout liquid
2) occurs only at boiling point
3) fast process
4) bubbles formed
what is condensation?
process in which a gas changes into liquid
what is condensation point?
temperature at which a gas changes into liquid
what happens during condensation?
as the temperature drops, gas particles lose energy and move more slowly, coming closer together
eventually, the movement of particles become slow enough for the gas to change into a liquid
what is sublimation?
process in which a solid changes into gas without going through the liquid phase
*only occurs because particles at surface of solid have enough energy to break away from solid and escape as gas
*opposite is deposition
what are 4 sublimable substances?
1) iodine (crystals)
2) ammonium chloride
3) dry ice (solid carbon dioxide)
4) naphthalene (in mothballs)
what is diffusion?
Chemistry
net movement of particles in liquids and gases from a region of higher concentration to a region of lower concentration until equilibrium is reached
why do 2 gases in a gas jar turn into a homogeneous/uniform mixture?
particles are in constant random motion
particles move from a region of higher concentration to a region of lower concentration until equilibrium is reached
bottom gas diffuses upwards while top gas diffuses downwards
eventually, both gases are evenly mixed, forming a homogeneous mixture
why do 2 liquids in a flask turn into a homogeneous/uniform colour (if any)?
particles are in constant random motion
solute/added solvent particles move from a region of higher concentration to a region of lower concentration through the water molecules (or solvent molecules) until equilibrium is reached
this causes water to turn uniformly (colour) or homogeneous
what are 2 factors affecting diffusion?
Chemistry
1) relative molecular mass
2) temperature
how does the relative molecular mass of a substance affect the rate of diffusion?
Chemistry
the greater the relative molecular mass, the slower the rate of diffusion
*e.g. ammonia (relative molecular mass: 17) diffuses faster (and moves a greater distance) than hydrogen chloride (relative molecular mass: 36.5)
how does the temperature affect the rate of diffusion?
Chemistry
the higher the temperature, the faster the rate of diffusion
