cgier 29 Flashcards
For a fixed mass of enclosed gas at constant temperature, the product of the pressure (P) and volume (V) remains constant.”
- Boyles law
- P . V = constant
- p1v1 = p2v2
For a fixed mass of enclosed gas at constant pressure the ratio of Volume to Temperature is constant”
-Charles law
- V/T = constant ( directly proportional )
- V1/T1 = V2/ T2
Charles law sets an absolute lower limit on T at
-273 celicus aka the absolute zero
the ideal gas law is the
-combination of boyels and Charles law
- PV = NRT
r= 8.314 j mol k-1
r= universal gas constant
- P1V1/T1 = P2V2/T2
- temp must be in k
the consequence of ideal gas law is
-reduction if temp corrosponds to the reduction of pressure
- so changes in pressure can be made to cause changes in temp
-Refrigerators & Air to (Water) Heat Pumps work by slowly compressing (to avoid heating) a closed volume of refrigerant gas and then rapidly removing the pressure (decompressing) which cools the gas.
sudden compression leads to
heating of gas tempreture
what pressure is negligible in gasses
gauge pressure effect ( variation of height P= p.g.h). regardless the containers shape, all gas will have the same pressure
true or false: air is a mixture of gases and each component of gas ignores the existence of another
true
of a gas in a gas mixture is the pressure it would exert if it, alone, occupied the volume.
partial pressure
states that the total pressure of a mixture of gases = the sum of partial pressures exerted by the gases if they were present separately
daltons law
states that the concentration or solubility of a gas in a liquid is proportional to the partial pressure of that gas above the surface
- Henry’s law
- this explains why drinks are fizzy
what happens to the solubility when we increase the pressure
-solibulty increases , no bubbles formed
- direct relationship
what law is relevant to ultrasonic cavitation - which is used to vaporise tumour tissue w/ high intensity ultrasound
Henry’s law
Relates the tension in a membrane to the pressure difference on either side.
Laplace law
- p = 2T/R or pi -p o = 2T/R
- t: tension r: radius
what 2 laws that produce action in the respiration in the lungs and alveoli for spherical membrane
boyels and Laplace
- boyels law: volume and the pressure within the perual space is controlled by the action of diaphragm
- interpleaural pressure is always less than atmospheric pressure ( except under forced exhalation max= 3 mm hg)