5. Solids, liquids, gases Flashcards
(23 cards)
density equation
density = mass / volume
pressure equation
pressure = force / area
what does pressure in a gas or liquid at rest do
act equally in all direction
pressure difference equation
pressure difference = height (depth) x density x gravitational field strength
PAPER 2
explain why heating a system will change the energy stored within the system and raise its temperature
???
Condensing / freezing
Bonds forming between particles
= energy released
Temp doesn’t go down until all substance has changed state
PAPER 2
explain why heating a system will change the energy stored within the system and produce changes of state
???
Melting / boiling
Energy used for breaking intermolecular bonds ( rather than raising temp )
Substance stays at constant temp
PAPER 2
Describe changes of state in melting ( solid to liquid )
heat energy= particles vibrate faster= forces between them are overcome
PAPER 2
Describe changes of state in boiling ( liquid to gas )
heat energy = particles move faster = increase in energy= overcome attraction between particles
PAPER 2
describe particles in a solid
Strong intermolecular forces of attraction
Vibrate around fixed position
Small distances between them ( close together )
PAPER 2
describe particles in a liquid
Weak intermolecular forces of attraction
Free to move around within the confines of the liquid
Move in random directions at low speeds
Close together but move past each other = irregular arrangements
PAPER 2
describe particles in a gas
Very weak/non-existent forces of attraction (bonds)
free to move around the container (random directions)
fast speeds ( high energy )
large distances between them.
PAPER 2
definition of specific heat capacity
the energy required to change the temperature of an object by one degree Celsius per kilogram of mass (J/kg*C)
PAPER 2
change in thermal energy equation ( specific heat capacity )
change in thermal energy = mass x specific heat capacity x change in temperature
explain the molecules in gas
random motion = constantly colliding = exert a force =pressure on walls of a container
what is absolute zero
-273*C
start of the Kelvin scale
coldest anything can get
atoms have as little kinetic energy as its possible to ger
how do u convert
- degrees C to kelvin
- kelvin to degrees C
- 273
2. - 273
what happens to gas molecules when you increase the temperature
increase average kinetic energy = particles vibrate faster = forces overcome = particles start to move around
if you double the temperature ( in kelvin) what happens to the average kinetic energy of the particles
it doubles
what is the rule of the temp ( in kelvin) and the av. kinetic energy of particles
the temp of a gas ( in kelvins) is proportional to the average kinetic energy of its particles
what is the equation for a fixed mass of gas at a constant temp.
pressure x volume = constant
equation ( short hand ) for gas at constant temp.
p1V1=p2V2
what is the equation for a fixed mass of gas at a constant volume
pressure / temp (in kelvin) = constant
equation ( short hand ) for gas at constant volume
p1 / T1 = p2 / T2
