The FT-IR spectra of mixtures of argon, ethene, ethyne, d6-benzene, fluorobenzene, CO, CO2, SO2, CCl4, CHC13, d6-acetone, ethanol, HCN, and Acrylonitrile in mixtures with HC1 have been recorded as gases and by matrix isolation. The features which are measured are: 1. The changes in the integrated intensity of lines in the rotation-vibration spectrum of the fundamental HC1 band as a function of nonspecific interactions with other components of the mixture. 2. Bands associated with specific interactions forming hydrogen bonded complexes in the gas and matrix isolated phase. The relationship between the two kinds of interactions is discussed.