Limitations of the Ideal Gas Law

Oct 13, 2025 by wbrum.org 113 views

What Pressure is Required to Compress 196.0 Liters of Air at 1.00 Atmosphere into a Cylinder Whose Volume is 26.0 Liters?

Understanding the Problem

The problem requires us to find the pressure required to compress 196.0 liters of air at 1.00 atmosphere into a cylinder with a volume of 26.0 liters. To solve this problem, we need to use the ideal gas law, which relates the pressure, volume, and temperature of a gas.

The Ideal Gas Law

The ideal gas law is given by the equation:

PV = nRT

where:

P is the pressure of the gas
V is the volume of the gas
n is the number of moles of the gas
R is the gas constant
T is the temperature of the gas

Given Values

We are given the following values:

V1 = 196.0 liters (initial volume)
P1 = 1.00 atmosphere (initial pressure)
V2 = 26.0 liters (final volume)
T = constant temperature (we assume that the temperature remains constant during the compression process)

Solving for Pressure

We can use the ideal gas law to solve for the final pressure P2. Since the temperature is constant, we can set up a proportionality between the initial and final states:

P1V1 = P2V2

We can rearrange this equation to solve for P2:

P2 = P1V1 / V2

Plugging in the Values

Now we can plug in the given values:

P2 = (1.00 atm)(196.0 L) / (26.0 L)

P2 = 7.54 atm

Significant Figures

We need to express our answer with the correct significant figures. Since the initial pressure has 3 significant figures, we can round our answer to 3 significant figures:

P2 = 7.54 atm

Units

We need to express our answer in the correct units. Since the initial pressure is given in atmospheres, we can express our answer in atmospheres as well.

Conclusion

In conclusion, the pressure required to compress 196.0 liters of air at 1.00 atmosphere into a cylinder with a volume of 26.0 liters is 7.54 atm.

Additional Discussion

The ideal gas law is a fundamental concept in physics and chemistry that relates the pressure, volume, and temperature of a gas. The law is based on the assumption that the gas molecules are point particles that do not interact with each other except through collisions.

The ideal gas law can be used to solve a wide range of problems involving gases, including the compression of gases, the expansion of gases, and the calculation of gas densities.

Real-World Applications

The ideal gas law has many real-world applications, including:

Air compressors: Air compressors use the ideal gas law to compress air to high pressures for use in various applications, such as powering tools and equipment.
Scuba diving: Scuba divers use the ideal gas law to calculate the pressure of the air in their scuba tanks and to plan their dives accordingly.
Gas cylinders: Gas cylinders are used to store gases at high pressures. The ideal gas law is used to calculate the pressure of the gas in the cylinder and to ensure that the cylinder is safe to use.

Limitations of the Ideal Gas Law

The ideal gas law is a simplified model that assumes that the gas molecules are point particles that do not interact with each other except through collisions. In reality, gas molecules do interact with each other through various forces, such as van der Waals forces and electrostatic forces.

As a result, the ideal gas law is not always accurate, especially at high pressures and low temperatures. In these cases, more complex models, such as the van der Waals equation, may be needed to accurately describe the behavior of the gas.

Conclusion

In conclusion, the ideal gas law is a fundamental concept in physics and chemistry that relates the pressure, volume, and temperature of a gas. The law is based on the assumption that the gas molecules are point particles that do not interact with each other except through collisions. The ideal gas law has many real-world applications, including air compressors, scuba diving, and gas cylinders. However, the law is not always accurate, especially at high pressures and low temperatures.
Q&A: What Pressure is Required to Compress 196.0 Liters of Air at 1.00 Atmosphere into a Cylinder Whose Volume is 26.0 Liters?

Q: What is the ideal gas law?

A: The ideal gas law is a fundamental concept in physics and chemistry that relates the pressure, volume, and temperature of a gas. It is given by the equation:

PV = nRT

where:

P is the pressure of the gas
V is the volume of the gas
n is the number of moles of the gas
R is the gas constant
T is the temperature of the gas

Q: What is the significance of the ideal gas law?

A: The ideal gas law is a simplified model that assumes that the gas molecules are point particles that do not interact with each other except through collisions. This model is useful for understanding the behavior of gases and for making predictions about the behavior of gases under different conditions.

Q: How is the ideal gas law used in real-world applications?

A: The ideal gas law is used in a wide range of real-world applications, including:

Air compressors: Air compressors use the ideal gas law to compress air to high pressures for use in various applications, such as powering tools and equipment.
Scuba diving: Scuba divers use the ideal gas law to calculate the pressure of the air in their scuba tanks and to plan their dives accordingly.
Gas cylinders: Gas cylinders are used to store gases at high pressures. The ideal gas law is used to calculate the pressure of the gas in the cylinder and to ensure that the cylinder is safe to use.

Q: What are some limitations of the ideal gas law?

A: The ideal gas law is a simplified model that assumes that the gas molecules are point particles that do not interact with each other except through collisions. In reality, gas molecules do interact with each other through various forces, such as van der Waals forces and electrostatic forces. As a result, the ideal gas law is not always accurate, especially at high pressures and low temperatures.

Q: What is the van der Waals equation?

A: The van der Waals equation is a more complex model that takes into account the interactions between gas molecules. It is given by the equation:

(P + a/V^2)(V - b) = RT

where:

P is the pressure of the gas
V is the volume of the gas
a and b are constants that depend on the properties of the gas
R is the gas constant
T is the temperature of the gas

Q: When should the van der Waals equation be used instead of the ideal gas law?

A: The van der Waals equation should be used instead of the ideal gas law when the gas is at high pressures or low temperatures. At these conditions, the interactions between gas molecules become significant, and the ideal gas law is no longer accurate.

Q: What is the significance of the number of moles (n) in the ideal gas law?

A: The number of moles (n) represents the amount of gas present in a given volume. It is a measure of the quantity of gas and is used to calculate the pressure, volume, and temperature of the gas.

Q: How is the number of moles (n) related to the mass of the gas?

A: The number of moles (n) is related to the mass of the gas through the molar mass of the gas. The molar mass is the mass of one mole of the gas and is typically expressed in units of grams per mole (g/mol).

Q: What is the relationship between the pressure and volume of a gas?

A: The pressure and volume of a gas are inversely proportional to each other. This means that as the pressure of a gas increases, its volume decreases, and vice versa.

Q: What is the relationship between the temperature and volume of a gas?

A: The temperature and volume of a gas are directly proportional to each other. This means that as the temperature of a gas increases, its volume also increases, and vice versa.

Q: What is the significance of the gas constant (R) in the ideal gas law?

A: The gas constant (R) is a fundamental constant that relates the pressure, volume, and temperature of a gas. It is a measure of the energy of the gas molecules and is used to calculate the pressure, volume, and temperature of the gas.

Q: What are some common units for expressing the gas constant (R)?

A: The gas constant (R) can be expressed in a variety of units, including:

J/mol·K (joules per mole per kelvin)
L·atm/mol·K (liters per atmosphere per mole per kelvin)
m^3·Pa/mol·K (cubic meters per pascal per mole per kelvin)

Q: What is the significance of the temperature (T) in the ideal gas law?

A: The temperature (T) represents the average kinetic energy of the gas molecules. It is a measure of the energy of the gas and is used to calculate the pressure, volume, and number of moles of the gas.

Q: How is the temperature (T) related to the pressure and volume of a gas?

A: The temperature (T) is related to the pressure and volume of a gas through the ideal gas law. As the temperature of a gas increases, its pressure and volume also increase, and vice versa.

Q: What are some common units for expressing the temperature (T)?

A: The temperature (T) can be expressed in a variety of units, including:

K (kelvin)
°C (degrees Celsius)
°F (degrees Fahrenheit)

Q: What is the significance of the pressure (P) in the ideal gas law?

A: The pressure (P) represents the force exerted by the gas molecules on the walls of their container. It is a measure of the energy of the gas and is used to calculate the volume, number of moles, and temperature of the gas.

Q: How is the pressure (P) related to the volume and number of moles of a gas?

A: The pressure (P) is related to the volume and number of moles of a gas through the ideal gas law. As the pressure of a gas increases, its volume and number of moles decrease, and vice versa.

Q: What are some common units for expressing the pressure (P)?

A: The pressure (P) can be expressed in a variety of units, including:

atm (atmospheres)
Pa (pascals)
psi (pounds per square inch)

Q: What is the significance of the volume (V) in the ideal gas law?

A: The volume (V) represents the amount of space occupied by the gas molecules. It is a measure of the size of the gas and is used to calculate the pressure, number of moles, and temperature of the gas.

Q: How is the volume (V) related to the pressure and number of moles of a gas?

A: The volume (V) is related to the pressure and number of moles of a gas through the ideal gas law. As the volume of a gas increases, its pressure and number of moles decrease, and vice versa.

Q: What are some common units for expressing the volume (V)?

A: The volume (V) can be expressed in a variety of units, including:

L (liters)
m^3 (cubic meters)
in^3 (cubic inches)

Q: What is the significance of the number of moles (n) in the ideal gas law?

A: The number of moles (n) represents the amount of gas present in a given volume. It is a measure of the quantity of gas and is used to calculate the pressure, volume, and temperature of the gas.

Q: How is the number of moles (n) related to the mass of the gas?

Q: What is the relationship between the number of moles (n) and the volume of a gas?

A: The number of moles (n) is related to the volume of a gas through the ideal gas law. As the number of moles of a gas increases, its volume also increases, and vice versa.

Q: What are some common units for expressing the number of moles (n)?

A: The number of moles (n) can be expressed in a variety of units, including:

mol (moles)
g/mol (grams per mole)
kg/mol (kilograms per mole)

Q: What is the significance of the gas constant (R) in the ideal gas law?

Q: What are some common units for expressing the gas constant (R)?

A: The gas constant (R) can be expressed in