Final answer:
The statement about molecular interactions affecting the real-gas equation of state and being expressed through virial coefficients is true. Virial coefficients correct the ideal gas law to reflect intermolecular attractions and molecular volumes, particularly under high pressures and low temperatures where ideal gas assumptions fail.
Step-by-step explanation:
In the context of real gases, the statement 'molecular interactions affect the equation of state; the true equation of state is expressed in terms of virial coefficients' is true. In ideal gas behavior, which is often defined under the condition of low pressure and high temperature, the volume of gas molecules and the intermolecular forces are assumed to be negligible. However, this assumption does not hold true for real gases, particularly when dealing with high pressures and low temperatures.
Real gases are affected by intermolecular attractions and the nonzero volumes of gas molecules. Under conditions where these factors become relevant, the ideal gas law (PV = nRT) must be corrected to account for these intermolecular forces and the finite size of the molecules. At low pressures, the correction factor for intermolecular attractions is more substantial, while at high pressures, the correction for the volume of the molecules cannot be ignored.
Virial coefficients in the virial equation of state provide a method to express these deviations from ideal behavior. They are crucial for accurately describing the thermodynamic properties of real gases and allow the equation of state to reflect the actual behavior of gases under various pressure and temperature conditions.