Using conventional absorption and picosecond double-resonance spectroscopy in the infrared the reaction kinetics of weak hydrogen bonds in liquids has been studied. By combination of the two methods the dissociation rate of hydrogen bonds formed between the components of binary mixtures can be determined. It is shown that the vibrational relaxation of such systems is characterized by two concentration-dependent decay constants. Experimental data for the liquid system CHBr3:C2D5OD are presented and discussed. A hydrogen bond dissociation rate of k(D) = (0.25 +/- 0.10) ps(-1) is obtained for weak hydrogen bonds between the components of this system.