chapter 8: Gases Flashcards
what are the percentages of gases in the air
N2 = 78 O2 = 21
the air we breathe is a…
mixture of gases
what are some characteristics of gases
- Spontaneously expand to fill their containers (no outside energy)
- highly compressible
- homogenous mixture
- low density
what happens when the gas particles collide with each other
creates pressure
what is pressure
force that results from the collisions
of gas particles divided by the area of the surface
with which they collide
what is the formula for pressure
P = F/A force = m x a
what does pressure depend on
of gas particles
fewer gas particles =
lower pressue
how does altitude affect pressure
pressure decreases above 30 k
- keep cabins pressurized
how does gravity affect the atomosphere
causes the atmosphere as a whole to press down on earth
what is atmospheric pressure
weight of air per unit of area
what is the si unit for force
newton (N)
what is the SI unit of pressure
N/m^2 or pascal (Pa)
who was pascal named after
Blaise Pascal
what is bar
used to report pressure; 10^5 Pa
who discovered atm,torr, mmhg
evangelista torricelli ( Galileo’s student)
who invented the mercury barometer
torricellu
what is standard atomospheric pressure
pressure @ sea lvl
what is the standard atms. press.
101325 Pa or 101.325 kPa
what non si units are w/ the atmospheric pressure
atm, mmhg m torr
what is a mamometer
measure pressure of enclosed gases
what did robert boyle do
investigated the relationship between the pressure
of a gas and its volume.
what was boyle’s law
volume and pressure are inverse @ constant temp