The ability of hydroxide Ion to produce carbanlons at 170°C In water has been determined by measuring the extent of deuteratlon and reexchange of deuterium labels for several organic acids and phenols. The results of the exchange reactions provide a rough estimate of the types of reactions that are possible between hydroxide Ion and wood components during alkaline pulping. It has been estimated that NaOH/H20 at 170° can deprotonate organic acids having pKavalues of about 35 and can produce polyanlon intermediates. Several experiments were directed toward understanding the effects of ct-hydroxyl groups and zinc ions on carbanion formation. Exchange reactions involving Na2S at 170° showed that this species is largely dissociated to NaOH and NaSH and that the latter does not contribute to the basicity of the solution.