Not
long
ago, in a chemistry
Mayso
the
FORCE/area
be with you
lab far far away…
1. Describe Gay-Lussac’s Law with a formula
2. Use Gay-Lussac’s Law to determine either
a temperature or volume
3. Combine all three laws into the Combined
Gas Law
4. Use the Combined Gas Law to determine
either temperature, volume or pressure
If n and V are
constant,
then P α T
P and T are directly
proportional.
P1 P2

T1 T2

If one temperature
goes up, the
pressure goes up!
Joseph Louis GayLussac (1778-1850)
Gay Lussac’s Law Summary
The pressure and temperature of a gas are
directly related, provided that the volume
remains constant.
P1 P2

T1 T2
P1
P2
T1
T2
3.00 atm
298 K
P2
325 K
3.3 atm
P1
P2
T1
T2
1.8 atm
1.9 atm
293 K
T2
310 K or
36 oC
Now let’s put all 3 laws
together into one big
law…….

The good news is that you don’t
have to remember all three gas
laws! Since they are all related
to each other, we can combine
them into a single equation. BE
SURE YOU KNOW THIS EQUATION!
PV
PV
1 1
2 2

T1
T2
No, it’s not related to R2D2
The Combined Gas Law
The combined gas law expresses the
relationship between pressure, volume and
temperature of a fixed amount of gas.
PV
PV
1 1
2 2

T1
T2
Boyle’s law, Gay-Lussac’s law, and Charles’
law are all derived from this by holding a
variable constant.
If you should only need one of the other
gas laws, you can cover up the item that
is constant and you will get that gas law!
P1 V1
T1
=
P2 V2
T2
Boyle’s Law
Charles’ Law
Gay-Lussac’s
Law
Greatest Reasons for Termination
from a Job
1.
The inability to get along with co-workers and
supervisors.
2.
Absenteeism
3.
Lack of interest
4.
Continuously making costly mistakes
5.
Does not follow directions
6.
Shows an unwillingness to learn
Hint #5. A record of data is essential. It
fools the instructor into thinking that you
were working.
1. Describe Gay-Lussac’s Law with a formula.
2. Use Gay-Lussac’s Law to determine either
a temperature or volume
3. Combine all three laws into the Combined
Gas Law
4. Use the Combined Gas Law to determine
either temperature, volume or pressure
P1
V1
(1.00 atm) (3.60 L)
P2
V2
2.50 atm (V2)
1.44 L
The End!!!