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The Boltzmann Factor and Partition Functions 79 3-12. An approximate partition function for a gas of hard spheres can be obtained from the partition function of a monatomic gas by replacing V in Equation 3.22 (and the following equation) by where b is related to the volume of the N hard spheres. Derive expressions for the energy and the pressure of this system. We can use the partition function specified in the problem to find In Q = + terms not involving T Substituting into Equation 3.21, we find that the energy (E) is the same as that for a monatomic ideal gas: T/2. We can use the partition function specified in the problem to find CENTRO In Q = N + terms not involving V We substitute into Equation 3.32 to find FÍSICA TECNOLOGIA AVANZADA BIBLIOTECA LOTHAN MAX LOSKE 3-13. Use the partition function in Problem 3-10 to calculate the heat capacity of a two-dimensional ideal gas. In Problem 3-10, we found that (E) = for the given partition function. Since (E) = U, we can substitute into Equation 3.25 to write 3-14. Use the partition function for a monatomic van der Waals gas given in Problem 3-11 to calculate the heat capacity of a monatomic van der Waals gas. Compare your result with that of a monatomic ideal gas. The partition function given in Problem 3-11 is In Problem 3.11, we found that (E) = for a monatomic van der Waals gas. Since (E) = U, we can substitute into Equation 3.25 to write The heat capacity of a monatomic van der Waals gas is the same as that of a monatomic ideal gas.