chapter 14 the behavior of gases. properties of gases compressibility – a measure of how much the...
TRANSCRIPT
![Page 1: Chapter 14 THE BEHAVIOR OF GASES. Properties of Gases Compressibility – a measure of how much the volume of matter decreases under pressure Gases](https://reader035.vdocument.in/reader035/viewer/2022062305/5697c0261a28abf838cd5d66/html5/thumbnails/1.jpg)
Chapter 14THE BEHAVIOR OF GASES
![Page 2: Chapter 14 THE BEHAVIOR OF GASES. Properties of Gases Compressibility – a measure of how much the volume of matter decreases under pressure Gases](https://reader035.vdocument.in/reader035/viewer/2022062305/5697c0261a28abf838cd5d66/html5/thumbnails/2.jpg)
Properties of Gases
Compressibility – a measure of how much the volume of matter decreases under pressure
Gases are easily compressed because of the space between the particles in a gas
![Page 3: Chapter 14 THE BEHAVIOR OF GASES. Properties of Gases Compressibility – a measure of how much the volume of matter decreases under pressure Gases](https://reader035.vdocument.in/reader035/viewer/2022062305/5697c0261a28abf838cd5d66/html5/thumbnails/3.jpg)
Factors Affecting Gas Pressure
1. The amount of gas
2. Volume
3. Temperature
![Page 4: Chapter 14 THE BEHAVIOR OF GASES. Properties of Gases Compressibility – a measure of how much the volume of matter decreases under pressure Gases](https://reader035.vdocument.in/reader035/viewer/2022062305/5697c0261a28abf838cd5d66/html5/thumbnails/4.jpg)
1. Amount of Gas
When a gas is pumped into a container:
pressure increases
Number of collisions increase
![Page 5: Chapter 14 THE BEHAVIOR OF GASES. Properties of Gases Compressibility – a measure of how much the volume of matter decreases under pressure Gases](https://reader035.vdocument.in/reader035/viewer/2022062305/5697c0261a28abf838cd5d66/html5/thumbnails/5.jpg)
![Page 6: Chapter 14 THE BEHAVIOR OF GASES. Properties of Gases Compressibility – a measure of how much the volume of matter decreases under pressure Gases](https://reader035.vdocument.in/reader035/viewer/2022062305/5697c0261a28abf838cd5d66/html5/thumbnails/6.jpg)
2. Volume
When volume decreases, pressure increases (inverse relationship)
If volume is doubled, pressure is halved
![Page 7: Chapter 14 THE BEHAVIOR OF GASES. Properties of Gases Compressibility – a measure of how much the volume of matter decreases under pressure Gases](https://reader035.vdocument.in/reader035/viewer/2022062305/5697c0261a28abf838cd5d66/html5/thumbnails/7.jpg)
3. Temperature (Kelvin)
As temperature increases, pressure increases (proportional)
If temperature (Kelvin) is doubled, pressure is doubled
![Page 8: Chapter 14 THE BEHAVIOR OF GASES. Properties of Gases Compressibility – a measure of how much the volume of matter decreases under pressure Gases](https://reader035.vdocument.in/reader035/viewer/2022062305/5697c0261a28abf838cd5d66/html5/thumbnails/8.jpg)
![Page 9: Chapter 14 THE BEHAVIOR OF GASES. Properties of Gases Compressibility – a measure of how much the volume of matter decreases under pressure Gases](https://reader035.vdocument.in/reader035/viewer/2022062305/5697c0261a28abf838cd5d66/html5/thumbnails/9.jpg)
Standard Temperature and Pressure (STP)
![Page 10: Chapter 14 THE BEHAVIOR OF GASES. Properties of Gases Compressibility – a measure of how much the volume of matter decreases under pressure Gases](https://reader035.vdocument.in/reader035/viewer/2022062305/5697c0261a28abf838cd5d66/html5/thumbnails/10.jpg)
The Gas Laws
1. Boyle’s Law: Pressure and Volume
2. Charles’s Law: Volume and Temperature
3. Gay-Lussac’s Law: Pressure and Temperature
4. The Combined Gas Law
![Page 11: Chapter 14 THE BEHAVIOR OF GASES. Properties of Gases Compressibility – a measure of how much the volume of matter decreases under pressure Gases](https://reader035.vdocument.in/reader035/viewer/2022062305/5697c0261a28abf838cd5d66/html5/thumbnails/11.jpg)
1. Boyle’s Law:Pressure and Volume
As the pressure increases, volume decreases, if temperature is constant
Inverse relationship
Table T
P1 x V1 = P2 x V2
![Page 12: Chapter 14 THE BEHAVIOR OF GASES. Properties of Gases Compressibility – a measure of how much the volume of matter decreases under pressure Gases](https://reader035.vdocument.in/reader035/viewer/2022062305/5697c0261a28abf838cd5d66/html5/thumbnails/12.jpg)
Boyle’s Law
![Page 13: Chapter 14 THE BEHAVIOR OF GASES. Properties of Gases Compressibility – a measure of how much the volume of matter decreases under pressure Gases](https://reader035.vdocument.in/reader035/viewer/2022062305/5697c0261a28abf838cd5d66/html5/thumbnails/13.jpg)
Graphs based on Boyle’s Law
Volume versus pressure
![Page 14: Chapter 14 THE BEHAVIOR OF GASES. Properties of Gases Compressibility – a measure of how much the volume of matter decreases under pressure Gases](https://reader035.vdocument.in/reader035/viewer/2022062305/5697c0261a28abf838cd5d66/html5/thumbnails/14.jpg)
Sample Exercise A balloon contains 30.0 L of helium gas at 103 kPa. What is the
volume of the helium when the balloon rises to an altitude where the pressure is only 25.0 kPa? (temperature remains constant)
Answer: 124 Liters
![Page 15: Chapter 14 THE BEHAVIOR OF GASES. Properties of Gases Compressibility – a measure of how much the volume of matter decreases under pressure Gases](https://reader035.vdocument.in/reader035/viewer/2022062305/5697c0261a28abf838cd5d66/html5/thumbnails/15.jpg)
Practice Exercise
Nitrous oxide (N2O) is used as an anesthetic. The pressure on 2.50 L of N2O changes from 105 kPa to 40.5 kPa. If the temperature does not change, what will the new volume be?
Answer: 6.48 Liters
![Page 16: Chapter 14 THE BEHAVIOR OF GASES. Properties of Gases Compressibility – a measure of how much the volume of matter decreases under pressure Gases](https://reader035.vdocument.in/reader035/viewer/2022062305/5697c0261a28abf838cd5d66/html5/thumbnails/16.jpg)
2. Charles’s Law:Volume and Temperature
As the temperature of an enclosed gas increases, the volume increases, if the pressure is constant
Direct relationship
V1 = V2
T1 T2
![Page 17: Chapter 14 THE BEHAVIOR OF GASES. Properties of Gases Compressibility – a measure of how much the volume of matter decreases under pressure Gases](https://reader035.vdocument.in/reader035/viewer/2022062305/5697c0261a28abf838cd5d66/html5/thumbnails/17.jpg)
Illustration of Charles’s Law
Volume of an enclosed gas as a function of temperature at constant pressure
The dashed line is an extrapolation to temperatures at which the substance is no longer a gas
![Page 18: Chapter 14 THE BEHAVIOR OF GASES. Properties of Gases Compressibility – a measure of how much the volume of matter decreases under pressure Gases](https://reader035.vdocument.in/reader035/viewer/2022062305/5697c0261a28abf838cd5d66/html5/thumbnails/18.jpg)
Sample Exercise
A balloon, inflated in an air-conditioned room at 27C, has a volume of 4.0L. The balloon is then heated to a temperature of 57C. What is the new volume of the balloon if the pressure remains constant?
Answer: 4.4 liters
![Page 19: Chapter 14 THE BEHAVIOR OF GASES. Properties of Gases Compressibility – a measure of how much the volume of matter decreases under pressure Gases](https://reader035.vdocument.in/reader035/viewer/2022062305/5697c0261a28abf838cd5d66/html5/thumbnails/19.jpg)
Practice Exercise
If a sample of gas occupies 6.8L at 327C, what will its volume be at 27C if the pressure does not change?
Answer: 3.4 Liters
![Page 20: Chapter 14 THE BEHAVIOR OF GASES. Properties of Gases Compressibility – a measure of how much the volume of matter decreases under pressure Gases](https://reader035.vdocument.in/reader035/viewer/2022062305/5697c0261a28abf838cd5d66/html5/thumbnails/20.jpg)
3. Gay-Lussac’s Law:Pressure and Temperature As the temperature of a gas increases, pressure
increases, if volume is constant
Direct relationship
P1 = P2
T1 T2
![Page 21: Chapter 14 THE BEHAVIOR OF GASES. Properties of Gases Compressibility – a measure of how much the volume of matter decreases under pressure Gases](https://reader035.vdocument.in/reader035/viewer/2022062305/5697c0261a28abf838cd5d66/html5/thumbnails/21.jpg)
Sample Exercise
A sample of nitrogen gas has a pressure of 6.58 kPa at 539 K. If the volume does not change, what will the pressure be at 211 K ?
Answer: 2.58 kPa
![Page 22: Chapter 14 THE BEHAVIOR OF GASES. Properties of Gases Compressibility – a measure of how much the volume of matter decreases under pressure Gases](https://reader035.vdocument.in/reader035/viewer/2022062305/5697c0261a28abf838cd5d66/html5/thumbnails/22.jpg)
Practice Exercise
The pressure in a car tire is 198 kPa at 27°C. After a long drive, the pressure is 225 kPa. What is the temperature of air in the tire? Assume that the volume is constant.
Answer: 341 Kelvin
![Page 23: Chapter 14 THE BEHAVIOR OF GASES. Properties of Gases Compressibility – a measure of how much the volume of matter decreases under pressure Gases](https://reader035.vdocument.in/reader035/viewer/2022062305/5697c0261a28abf838cd5d66/html5/thumbnails/23.jpg)
4. The Combined Gas Law
![Page 24: Chapter 14 THE BEHAVIOR OF GASES. Properties of Gases Compressibility – a measure of how much the volume of matter decreases under pressure Gases](https://reader035.vdocument.in/reader035/viewer/2022062305/5697c0261a28abf838cd5d66/html5/thumbnails/24.jpg)
Sample Exercise
A 5.00 L air sample has a pressure of 107 kPa at a temperature of -50°C. If the temperature is raised to 102°C and the volume expands to 7.00 L, what will the new pressure be?
Answer : 129 kPa
![Page 25: Chapter 14 THE BEHAVIOR OF GASES. Properties of Gases Compressibility – a measure of how much the volume of matter decreases under pressure Gases](https://reader035.vdocument.in/reader035/viewer/2022062305/5697c0261a28abf838cd5d66/html5/thumbnails/25.jpg)
Sample Exercise
The volume of a gas filled balloon is 30.0 L and 313 K and 153 kPa pressure. What would the volume be at standard temperature and pressure?
Answer : 39.5 Liters
![Page 26: Chapter 14 THE BEHAVIOR OF GASES. Properties of Gases Compressibility – a measure of how much the volume of matter decreases under pressure Gases](https://reader035.vdocument.in/reader035/viewer/2022062305/5697c0261a28abf838cd5d66/html5/thumbnails/26.jpg)
Diffusion – the tendency of molecules to move toward areas of lower concentration until the concentration is uniform throughout
Effusion – a gas escapes through a tiny hole in its container
Gases with a lower molar mass (g/mol) diffuse and effuse faster than a gas with a higher molar mass.
![Page 27: Chapter 14 THE BEHAVIOR OF GASES. Properties of Gases Compressibility – a measure of how much the volume of matter decreases under pressure Gases](https://reader035.vdocument.in/reader035/viewer/2022062305/5697c0261a28abf838cd5d66/html5/thumbnails/27.jpg)
Ideal Gases and Real Gases1. Ideal Gases Particles have no volume There is no attraction between molecules
Ideal gases do not exist (kind of: H2 and He behave Ideally)
Needs high temperature and low pressure
2. Real Gases Have volume There are attractions between molecules (can
condense) Needs low temperature and high pressure
![Page 28: Chapter 14 THE BEHAVIOR OF GASES. Properties of Gases Compressibility – a measure of how much the volume of matter decreases under pressure Gases](https://reader035.vdocument.in/reader035/viewer/2022062305/5697c0261a28abf838cd5d66/html5/thumbnails/28.jpg)
Ideal Gases
Calculates the number of moles (n) of a contained gas
PV = nRT
Ideal gas constant (R) = 8.31
![Page 29: Chapter 14 THE BEHAVIOR OF GASES. Properties of Gases Compressibility – a measure of how much the volume of matter decreases under pressure Gases](https://reader035.vdocument.in/reader035/viewer/2022062305/5697c0261a28abf838cd5d66/html5/thumbnails/29.jpg)
Sample Exercise
A deep underground cavern contains 2.24 x 106
L of methane gas (CH4) at a pressure of 1.50 x 103 kPa and a temperature of 315 K. How many kilograms of CH4 does the cavern contain?
![Page 30: Chapter 14 THE BEHAVIOR OF GASES. Properties of Gases Compressibility – a measure of how much the volume of matter decreases under pressure Gases](https://reader035.vdocument.in/reader035/viewer/2022062305/5697c0261a28abf838cd5d66/html5/thumbnails/30.jpg)
Practice Problems
A child’s lungs can hold 2.20 L. How many grams of air do her lungs hold at a pressure of 102 kPa and a body temperature of 37°C? Use a molar mass of 29 grams (per mole) for air, which is about 20% O2 (32 g/mol) and 80% N2 (28 g/mol)