Consider a container filled with an ideal gas at a temperature of 300 K. The container has a volume of 0.1 . The gas contains 1.0 ×
gas molecules.
Each molecule has a mass of 2.0 × kg.
Calculate the pressure exerted by the gas on the walls of the container, based on the given assumptions.
1.46 × 10−20 Pa
1.36 × 10−22 Pa
2.45 × 10−12 Pa
1.47 × 10−18 Pa
Given data:
Temperature (T) = 300 K
Volume (V ) = 0.1
Number of molecules (N) = 1.0 × 10
Mass of each molecule (m) = 2.0 × kg
Boltzmann constant (k) = 1.38 × J/K
We can use the ideal gas law to relate the pressure (P), volume (V ), number of molecules (N), and temperature (T):
P V = N kT
First, let’s find the total kinetic energy (KE) of the gas molecules using the given temperature:
Where the factor accounts for the three degrees of freedom per molecule in 3D motion.
Substitute the value of KE into the equation for P V :
Now, we’ll calculate KE and then substitute it into the equation to find the pressure P:
Substitute KE into P V = KE:
Pressure is defined as force per unit area. Since we’re assuming no inter-molecular forces and no gravitational effects, the force is simply the change in momentum due to collisions. In a single collision, the change in momentum(?p) is 2m · v, where m is the mass of a molecule and v is its velocity.
Since the average velocity in each direction is zero, the average magnitude of velocity ( ?v) is also zero. However, the average squared magnitude of velocity
can be calculated from the temperature using the formula
Now, we can calculate the change in momentum (?p) per collision:
Finally, we can calculate the pressure P as the rate of change of momentum per unit area:
The area A is the area of the container’s walls. Assuming a cube-shaped container, all sides have the same area, so we’ll consider one of the sides. Let’s say the length of each side is L, then A = .
For a cubic container with a volume of V = , given that V = 0.1
, we can solve for L:
Now we can calculate the area A:
Substitute ?p and A into the pressure formula:
Since 1 N/ = 1 Pa, the pressure is approximately 1.36 ×
Pa.
Therefore, the correct option is 2.