J(1-) reaction can be carried out with I(1-), Fe(2+) or Co(2+);;

acetate in water Kinetics; K4P2O8 concn. from 1.91E-3-1.15E-2 M, hydrazine concn. 2.0E-2-8.0E-2 M,acetate buffer concn. from 1.2E-2-9.0E-2 M, pH=3.29-4.39, 40°C; reaction depends on concn. of K4P2O8 and N2H5ClO4 (precursor of N2H4) and pH; mechanism discussed;; iodometry;;