Warm-up
PROPERTY
SOLIDS
LIQUIDS
GASES
VOLUME
SHAPE
Fill in the table above with definite or not definite
olive oil
molasses
lotion
rubbing alcohol
Which liquid has the highest viscosity?
Which liquid has the lowest viscosity?
Section 15-2:
Behavior of Gases
Boyle’s, Charles’s
rd
and the 3 Law
How full do you inflate a
balloon for the Macy’s
Thanksgiving Day Parade?
The physical behavior of gas
can be described by
pressure (P), volume (V),
and temperature (T)
P, V, & T are interdependent
(changing one, affects the others)
•VOLUME
*amount of space matter fills
*measured in cm3, mL, L
*volume of a gas, is the
volume of its container
•TEMPERATURE
*measure of the average motion
of the particles of a substance
(remember - all particles move)
*speedometer for particles
*example: 20°C (room temp) is about 500 m/sec
•TEMPERATURE
*measured in Celsius,
Kelvin, or Farenheit
Low temperature: Cold particles, low energy, huddle to stay warm
High Temperature: Hot particles, high energy, spread out
•PRESSURE =
FORCE
AREA
( in units of kPa)
*force of the outward push of
the particles on their container
Gas flows from areas of:
High
Pressure
Low
Pressure
Questions:
Why does an
inflated ball leak
when punctured?
Why is a deflated
balloon never
completely flat?
BOYLE’S LAW
Robert Boyle
(1627-1691)
British scientist
Boyle’s Law
(squeeze a zit)
T as P
or
T as P
V
V
At a constant temperature, as the
pressure increases the volume
decreases, as the pressure decreases
the volume increases
Boyle’s Law: Varies Inversely
Boyle’s Law
What happens to helium
balloons that are released
and float to the heavens?
Charles’s Law
Jacques Alexandre
César Charles
(1746–1823),
French scientist
P as T
or
P as T
V
V
Charles’s Law
(Charlie leaves his flexible, basketball outside)
At a constant pressure, as the temperature
increases (particles move faster, collide more) the
volume increases, as the temperature decreases
the volume decreases
Charles’s Law: Directly Proportional
Charles’s Law
If Charlie leaves his
basketball outside,
why is it deflated in the
morning and fine by
noon?
rd
3
V as T
or
V as T
LAW
Rigid propane tank outside
P
P
At a constant volume, as the
temperature increases (particles move
faster, collide more) the pressure
increases, as the temperature
decreases the pressure decreases
3rd Law
18-wheeler truck
with rigid tires
How full should a
truck driver fill his
tires in the morning,
if he will be driving
to Las Vegas,
across the desert?
Summary of Gas Laws
Zit
Boyles Law
(inverse)
•T
P
V
Flexible
Basketball
Charles’s Law
(direct)
•P
T
V
Rigid
Propane
3rd Law
(direct)
•V
T
P