Benzoic acid and phenol both are insoluble in water due to non-polar benzene ring but these molecules become soluble if we react them with an aqueous solution of NaOH, which forms water-soluble sodium salt of the benzoic acid (Sodium benzoate) and the sodium salt of phenol (sodium phenoxide). But when these compounds reacted with an aqueous solution of NaHCO₃, benzoic acid reacted, but phenol is unable to react as it is comparatively weaker acid, so unable to form a salt with a weaker base (NaHCO₃).