Gases Flashcards
Which forces are weak in gases compared to liquids and solids?
Cohesion forces
2 kinds of gases
Perfect/ideal gases
Real gases
When are gases perfect/ideal?
Volume is negligible
No forces of attraction or repulsion exerted
No loss of energy during collisions (perfectly elastic collisions)
Equation of state that ideal gases obey
pV=nRT
What is absolute zero?
Lowest possible temperature theoretically possible to reach where thermal motion of particles cease entirely
What does Avogadro’s law state?
That at the same pressure, temperature and volume different gasses contain the same number of molecules
pV=? at constant temperature
Constant
What is an isothermal transformation?
Transformation under constant temperature
At constant pressure V=?* T
Constant
What is an isobaric transformation?
Transformation where the pressure is constant. The volume of the gas is proportional to the temperature
What is the first law of Gay-Lussac (Charles’ law)?
At constant pressure, the volume of a gas is directly proportional to its absolute temperature
Va/Ta=Vb/Tb
p=?*T at constant volume?
Constant
What is an isochoric transformation?
Transformation at constant volume.
The gas pressure is proportional to the temperature
Formula for second law of Gay-Lussac
pa/Ta=pb/Tb
At constant volume
What happens to (atmospheric pressure) when altitude increases?
Pressure decreases
What kind of forces are present in real gases?
Non-negligible interaction forces (attractive or repulsive)
What happens to kinetic and potential energy in gases when the temperature increases and the pressure decreases?
Potential energy decreases in favour of kinetic energy
When does the behaviour of real gasses approach that of ideal gasses?
High temp, low pressure
When are a liquid and a gas in equilibrium?
When gas pressure in the liquid equals the partial pressure of the gas
The number of molecules that enter the solution in the unit of time=number of molecule that evaporate
What are perfect gasses considered?
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