Gases Flashcards
Kinetic molecular theory
- collection of particles are in constant motion
- no attraction or repulsions between molecules; they collide like billiard balls
- large amount of space between particles relative to the size of the particles themselves
- Particles move with increased speed when temp. is increased.
Gas molecules are in ____________.
constant motion
What happens when gas molecules move and strike a surface?
they push or exert force on a surface.
Define pressure
the total amt. of force exerted by gas molecules hitting the entire surface at any one instant
How is pressure found?
P=F/A
P= pressure
F= force
A= area
How is pressure created with a gas?
it is the result of the constant movement of gas molecules and collisions with the surfaces around them.
What are the factors that the pressure of a gas depends on?
1) the number of gas particles in a given volume
2) volume of the container
3) average speed of the gas particles
How is air pressure measured?
with a barometer
How does a barometer work?
A column of mercury is supported by air pressure. The force of the air on the surface of the mercury balanced by the pull of gravity on the column of mercury.
An increase in particle in a volume of space will increase what?
pressure
atm
atmosphere
1 atm (exactly) = 760 (exactly) mmHG = 760 torr (exactly) = 14.7 psi, lbs/in squared
What are the common units of pressure?
Pascals (Pa) Kilopascals (kPa) Atmosphere (atm) Millimeters of mercury (mmHg) Inches of Mercury (inHg) Torr (torr) Pounds per square inch (psi, lbs./in squared)
mmHg
Millimeters of mercury
1 atm (exactly) = 760 (exactly) mmHG = 760 torr (exactly) = 14.7 psi, lbs/in squared
torr
Torr (unit of pressure)
1 atm (exactly) = 760 (exactly) mmHG = 760 torr (exactly) = 14.7 psi, lbs/in squared
psi
Pounds per square inch
1 atm (exactly) = 760 (exactly) mmHG = 760 torr (exactly) = 14.7 psi, lbs/in squared
Boyle’s Law
- Pressure of a gas is inversely proportional to its volume.
- temp is constant
- amt. of gas is constant
- as P increases V decreases by same factor
- PxV= constant
What is the formula for Boyle’s law?
P1xV1=P2xV2