There is no direct equivalent to the ideal gas law for liquids due to their complex molecular interactions, which differ significantly from gases. The relationship between pressure, volume, and temperature in liquids is influenced by the incompressibility of fluids, making them more complex to analyze. Unlike gases, where molecules can be treated as non-interacting points, liquids require consideration of molecular interactions. The discussion emphasizes that pressure and temperature in liquids cannot be simplified in the same way as in gases. Therefore, the ideal gas law does not apply to liquids.