Gases and Thermo Flashcards
(56 cards)
gases
a collection of particles moving at random through a primarily empty space
gas pressure
force exerted by the collisions of randomly moving particles with the walls of a container
1 atm = ___ mmHg = _____torr
760
avagadros law
volume of a gas at constant T and P is proportional to the number of moles of gas
boyles law
volume of a fixed amount of gas at a constant temp is inversely proportional to pressure
charles law
volume of a fixed amount of gas at a constant pressure is proportional to the absolute temp
standard temp and pressure
0C and 1 atm
partial pressure
the pressure a gas would have if it was the only gas in the container
daltons law of partial pressures
total pressure is equal to the sum of the partial pressures
the fraction of the total pressure contributed by each gas is equal to its
mole fraction
5 rules of kinetic molecular theory of gases
- a gas consists of tiny particles moving at random
- the volume of these particles themselves is negligible compared to the total volume
- gas particles act independently of eachother
- collisions of gas particles are elastic
- average kinetic energy of the particles is proportional to the Kelvin temp
elastic collisions
bounce off of other things at the same speed at which they hit
gas diffusion
the mixing of different molecules by random molecular motion with frequent collisions
gas effusion
gas molecules escape without collisions through a tiny hole into a vacuum
what two assumptions about gases are not valid at high temps
- that the volume of a pas particles is negligible
- that there are no attractive forces between particles
phase changes
change of state
fusion (solid-liquid)
ΔH +
ΔS +
freezing (liquid-solid)
ΔH -
ΔS -
vaporization (liquid-gas)
ΔH +
ΔS +
condensation (gas-liquid)
ΔH -
ΔS -
sublimation (solid-gas)
ΔH +
ΔS -
deposition (gas-solid)
ΔH -
ΔS -
if both ΔH and ΔS are +, reaction is favored at
high temp
if both ΔH and ΔS are -, reaction is favored at
low temp
