Subzero-temperature preservation of reactive fluids in the undercooled state. I. The reduction of potassium ferricyanide by potassium cyanide.

Many reactions show enhanced rates at subzero temperatures due to freeze concentration. The reduction of potassium ferricyanide by potassium cyanide has been studied at subzero temperatures in both the undercooled and the frozen state. The pseudo-first-order rate constants calculated differ greatly from those in previous reports. A high degree of freeze concentration and supersaturation in frozen bulk solutions occurs. It has been clearly demonstrated that undercooled preservation provides a useful method for the long-term storage of reactive mixtures.