Bell Ringer Quiz 1. 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.

Bell Ringer Quiz1. 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?

0.36 L

2. 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?

1.3 L

3. What are the following elements: Hf, Os, Pb, Au, Rn, Fr, W

Hafnium, Osmium, Lead, Gold, Radon, Francium, Tungsten

Important Concepts:Gay-Lussac Gas Law

Ideal Gas LawKinetic Theory of GasesIdeal Behavior of Gases

Gay-Lussac Gas LawIdeal Gas Law

Boyle’s Law ReviewBoyle’s Law relates

pressure and volumeP1V1= 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 ReviewCharles’ 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 LawGay-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 LawGay-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 #1If 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 T2 = 135 K

P1 = 689 torr P2 = x torr

Practice Problem #1If 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 T2 = x K

P1 = 300.2 kPa P2 = 101.13 kPa

Combined Gas LawBoyle’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 #2If 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 T2 = 238.1 K

P1 = 1 atm P2 = 0.86 atm

V1 = 1.0 L V2 = x L

A New Gas LawWith 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.1. What was always kept constant in all 4 gas laws?

Number of particles

2. When each gas law was solved for one half of the equation what was seen to be true?

It was found to be a constant

3. If each gas law keeps the number of particles the same, what would happen if we changed the number of particles?

A new gas law would need to be derived

Deriving the Ideal Gas LawIf 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 increaseThe volume would increaseThe temperature would

increaseSince all of these variables

increase with an increase in particles what is the relationship between these variables?Directly proportional

Ideal Gas LawKnowing 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 LawNow 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 #3A 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 1What does STP stand for AND what are the

values associated with it?A. Saturated temperature point AND 0 0C at 1

atmB. Standard temperature and pressure AND 0

0C at 1 atmC. Standing Tempo Pianissimo and 100 0C at 0

atmD. Standard temperature and pressure AND

100 0C at 0 atm

Question 2What causes gases to not behave ideally?

A. High PressureB. Bad upbringingC. Being to hotD. Low temperatureE. Low pressureF. Improper measuring

Question 3What happens to the molecules of gas if

the temperature is increased AND what happens to the pressure?A. The molecules slow downB. The molecules stick togetherC. The molecules speed upD. The pressure decreasesE. The pressure increasesF. The pressure stays the same

Question 4What is the direct measure of average

kinetic energy?A. DensityB. PressureC. VolumeD. TemperatureE. Conductivity

Question 5What 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