NaClO4 in water Kinetics; soln. of cis-PtCl(NH3)2(OH2)(1+) in 1.0 M NaClO4 and 0.1 M HClO4 and 0.1 M NaHmal soln. (I=1.0 M NaClO4) rapidly mixed at pH 4.3 and temp. 37.3-50.0°C; monitored spectrophotometrically at 245 and 290 nm;