Transcript Bell Ringer Quiz

Bell Ringer Quiz
A gas bubble is squeezed with 7.42 atm of pressure. The
bubble started at a size of 2.7 L under STP conditions. What
is the size of the bubble once it is squeezed?
1.

0.36 L
Knowing that Charles’ Law deals with temperature and
volume, what does 2.6 L change to when the temperature is
decreased from 200 K to 100 K?
2.

1.3 L
What are the following elements: Hf, Os, Pb, Au, Rn, Fr, W
3.

Hafnium, Osmium, Lead, Gold, Radon, Francium, Tungsten
Gay-Lussac Gas Law
Ideal Gas Law
Important Concepts:
Gay-Lussac Gas Law
Ideal Gas Law
Kinetic Theory of Gases
Ideal Behavior of Gases
Boyle’s Law Review
 Boyle’s Law relates pressure
and volume
 P1V1= P2V2
 The relationship between
pressure and volume is
known as what type of
relationship?
 Inverse Relationship
 What two variables are held
constant for Boyle’s Law?
 Number of particles and
temperature
Charles’ Law Review
 Charles’ Law relates volume
and temperature
 The relationship between
volume and temperature is
known as what type of
relationship?
 Directly Proportional
 What is held constant for
Charles’ Law?
 Number of particles and
pressure
Absolute Zero and Kelvin Scale
 Absolute zero is the temperature
at which the volume of a gas
becomes zero when the a plot of
the volume versus temperature for
a gas are extrapolated. As expected,
the value of absolute zero obtained
by extrapolating the data is
essentially the same as the value
obtained from the graph of pressure
versus temperature in the
preceding section. Absolute zero
can therefore be more accurately
defined as the temperature at which
the pressure and the volume of a
gas extrapolate to zero.
 A plot of the volume versus the
temperature of a gas (when the
temperatures obtained are
converted from Celsius to the
Kelvin scale) becomes a straight
line that passes through the origin.
Any two points along this line can
therefore be used to construct the
following equation, which is known
as Charles' law.
 Before using this equation, it is
important to remember that
temperatures must be converted
from C to K
Gay-Lussac’s Law
 Gay-Lussac was a French
Chemist who discovered the
relationship between
temperature and pressure
 He kept volume and the
number of particles constant
 His testing found that as
temperature increases the
pressure inside a fixed
volume increases
 This relationship is known as
a directly proportional
relationship
Gay-Lussac’s Law
 Gay-Lussac’s Law states that
pressure in directly proportional
to temperature in a closed
volume that does not change
 He found that the relationship
between pressure and
temperature was always constant
 He found that
 Knowing this he set both sides
equal and derived his law:
Example Problem #1
 If a container is heated from 100 K to 135 K that had an
initial pressure of 689 torr, what is its pressure after being
heated?
T1 = 100 K
P1 = 689 torr
T2 = 135 K
P2 = x torr
Practice Problem #1
 If a steel container has an internal pressure of 300.2 kPa with
a temperature of 273 K is submersed in water. The new
pressure inside the container is 101.13 kPa. The container
and the water reach equilibrium. What is the temperature of
the water?
T1 = 273 K
P1 = 300.2 kPa
T2 = x K
P2 = 101.13 kPa
Combined Gas Law
 Boyle’s, Charles’, and Gay-Lussac’s Laws deal with pressure,
volume, and temperature.
 In the natural world, is it possible to separate pressure,
volume, and temperature?
 In the natural world, these three variables are intertwined and
need to be accounted for when dealing with gas properties
 To account for this inseparability, a gas law was devised to
incorporate all three variables.
 This gas law is known as the combined gas law which states
the following
Example Problem #2
 If a balloon was inflated with He at STP conditions and had a
volume of 1.0 L was released and reached an elevation where
the pressure was 0.86 atm and 238.1 K, what would the new
volume of the balloon be?
T1 = 273 K
P1 = 1 atm
V1 = 1.0 L
T2 = 238.1 K
P2 = 0.86 atm
V2 = x L
A New Gas Law
 With the discovery of the combined gas law, we are now able
to take the final step in the gas laws.
 Let’s make some observations and deductions about the gas
laws.
What was always kept constant in all 4 gas laws?
1.

Number of particles
When each gas law was solved for one half of the equation
what was seen to be true?
2.

It was found to be a constant
If each gas law keeps the number of particles the same, what
would happen if we changed the number of particles?
3.

A new gas law would need to be derived
Deriving the Ideal Gas Law
 If we add in more gas particles to a




balloon, what do you predict will
happen to the pressure,
temperature, and volume of the
balloon?
The pressure would increase
The volume would increase
The temperature would increase
Since all of these variables increase
with an increase in particles what is
the relationship between these
variables?
 Directly proportional
Ideal Gas Law
 Knowing that volume, pressure, and temperature are directly
proportional to the number of particles, we can add number
of particles (n) to our previously discovered combined gas
law to make this relationship:
 Without even knowing it, we have derived what is known as
the Ideal Gas Law
 The constant k in the above equation is known as the gas
constant actually known as R
 R is equal to 0.082057461(L*atm)/(K* mol )
is back!!
Ideal Gas Law
 Now that we know that k = R for the ideal gas law we can now
setup the Ideal Gas Law
 For this law scientists made n equal to moles and not number of
particles to make the math easier to handle
 Knowing the ideal gas law makes remembering the other 4 gas laws
pointless… WHY!?!
WHY?!?
 Remembering the other gas laws becomes pointless because
if you set the ideal gas law equal to R and the set it equal to
itself anything that is held constant on both sides will cancel
out.
 Do you see the other gas laws?
Example Problem #3
 A vessel contains 2.87 moles of CO. The volume of the
container is 3.8 L and it has a temperature of 243 K. What is
the pressure inside the container?
Quiz
Question 1
 What does STP stand for AND what are the values associated
with it?
A. Saturated temperature point AND 0 0C at 1 atm
B. Standard temperature and pressure AND 0 0C at 1 atm
C. Standing Tempo Pianissimo and 100 0C at 0 atm
D. Standard temperature and pressure AND 100 0C at 0 atm
Question 2
 What causes gases to not behave ideally?
A. High Pressure
B. Bad upbringing
C. Being to hot
D. Low temperature
E. Low pressure
F.
Improper measuring
Question 3
 What happens to the molecules of gas if the temperature is
increased AND what happens to the pressure?
A. The molecules slow down
B. The molecules stick together
C. The molecules speed up
D. The pressure decreases
E. The pressure increases
F.
The pressure stays the same
Question 4
 What is the direct measure of average kinetic energy?
Density
B. Pressure
C. Volume
D. Temperature
E. Conductivity
A.
Question 5
 What is an ideal gas?
A. A gas that interacts with its neighbor gas particles, can stop,
and stick together
B. A gas that elastically bounces, has constant motion, no
attraction or repulsion
C. A gas that elastically bounces but stops from time to time
D. A unstoppable particle that cannot be contained except by the
incredible hulk