Boyle’s Law and
Charles’ Law
Volume: What’s the Matter?
Solids and liquids have a
definite volume. The container of
a liquid or a solid may change,
but the volume will remain the
same. For example, 50 ml of
water will stay 50 ml of water no
matter what size the container.
Likewise, if you put a Jolly
Rancher in a huge container, it
will still stay the same size (even
though we might wish for it to
get bigger!)
Volume is the amount of space
something takes up.(size)
Think – Pair – Share
• What is the shape of
a gas?
• What is the volume of
a gas?
• Can the volume of a
gas change?
• Can the spacing
between the particles
of a gas change?
Gases behave differently.
Think of a balloon. What
happens when it pops?
Where does the air go?
Think about when you put
more air into a tire. What
happens to the spacing of
the particles that were
inside the tire already?
Name 3 unique
characteristics of gases.
(think – pair – share)
Unique Characteristics of
Gases
•Gases take the shape of their containers
(think balloon and tire) In other words, they
do not have a definite shape.
•Gases do not have definite volumes.
They fill their containers (think of the
balloon popping in a room)
•The amount of empty space can change
in a gas (Think of filling a beach ball or
tire)
Pressure is the
amount of force
exerted on a given
area. A beach ball
has fewer particles of
gas colliding inside of
it than a basketball.
Fewer collisions
mean less force.
Less force=less
pressure.
How can you prove
this?
How Gases Behave Under
Pressure
video
Imagine a diver at a depth of 10
meters blowing a bubble of air.
As the bubble rises, its volume
increases. By the time the
bubble reaches the surface, its
original volume will have
doubled as a result of the
decrease in pressure. (What
happens to water pressure at
the top of the water?)
Why do balloonists have to be
careful about how much helium
they use to fill their
balloon?(What happens to the
atmospheric pressure the
higher you go in the
atmosphere?)
Robert Boyle
The Honorable Robert
Boyle (January 25, 1627 December 30, 1691) was
an Irish natural
philosopher , chemist,
physicist, and inventor,
noted for his work in
physics and chemistry.
He is largely regarded
today as the first modern
chemist.
Boyle’s Law
This law states that
for a fixed amount of
gas at a constant
temperature, the
volume of a gas
increases as its
pressure decreases.
Likewise, the volume
of the gas decreases
as its pressure
increases.
As the P
the V
As the P
the V
Boyle’s Law
The V
The V
as the P
as the P
What do the V and P stand for in this
diagram? Explain
How Gases React as the
Temperature Changes
Video
Jacques Charles
Jacques Charles was
an 18th Century (born
in the 1700’s) French
inventor, scientist,
mathematician and
balloonist. He made
the first flight in a
hydrogen balloon on
August 27, 1783.
Charles’s Law
Charles’ Law states that for
a fixed amount of gas at a
constant pressure, the
volume of the gas
increases as its
temperature increases.
Likewise, the volume of the
gas decreases as its
temperature decreases.
Explain what would happen
to this balloon if taken
outside on a cold winter
day
Graphing Charles’ Law
Charles’ Law
The V
as the T
The V
as the T
What do the V and the T
stand for in this diagram?
Explain
Charles’s Law and Bicycle Tires
Exit Ticket
One of your friends
over inflated the tires
on her bicycle. Use
Charles’s Law to
explain why she
should let out some of
the air before going
for a ride on a hot
day.