Laserfiche WebLink
i <br /> • Substance Metal - �5upporting Eleclralyle - End Point --- — <br /> Determined Tilrent Elect Procedure or Remarks (E vs SCE) <br /> Ag+ I- Ag 001 M HNO3 +0 102V <br /> As043- Ag+ Ag Mainialn at pH 9 <br /> Ad+ Ascorbic Pt pH 16-3,50"C AE Max <br /> i 8r- Agi+ Ag OOIM HNO3 -4 0 195V <br /> cl- Ag+ Ag OOIM HNO3 4 0270V <br /> Cr207 As3+ Pt 20% H2SO4 AE Max <br /> Cu2+ Cr2+ Hg(Ag 5M HCI,deaerate w1CO2 -0 IV <br /> Tipped in Hg) <br /> Fel+ Mn04- Pl 0 2- 1 M H2SO4 + 1 09V <br /> Cr207= Pt 05M H2SO4 AE Max <br /> i Fe(CN)64- Cr207= Pt 7% HCl,50-C AE Max <br /> Halide Mix Ag+ Ag 001M HNO3, contg 5% wlv <br /> Ba(NO3)2 <br /> H2S03,SO2 Mn04_ PI 0 5M H2SO4,Add excess std QE Max <br /> Mn04-, then excess 1- and <br /> Back-Titrate <br /> I" Ag+ Ag OOIM MN03 _ +0 102V <br /> Mn04- Pt u 1 0 25M "2SO4 + 1 OV <br />' Mercaptans Alc Ag Solv 13 79 Na0Ac J1120 4 6 nil S = Isl break <br /> 001M glacial HOAC -1 500 Fill McOH dil (Not accurate) <br /> Ag+ to one liter with CGHG Denerale Mercaptan <br /> with N2 2nd break <br />' Mn2+ Mn04" Pt Add acid sorn or sample to 250 int +0 53V <br /> frosh sal d N84P207 soin Adjust <br /> to pH 5 7 and Iltrate <br /> S= Ag+ Ag <br /> Sb5+ Br03- Pt To sample In 5% HCI add excess +0 3 to 0 5V <br /> TO+, then lmmed 3 dps 3% CUSO4 <br /> Stir + Titrate <br /> SCN Ag+ Ag 001 M HNO3 Conig Ba(NO3)2 +021V <br /> TI4+ Cr2+ Hg(Ag 2M H2SO4 deaerate wiCO2 0 30V <br />' Tipped In Hg) <br /> V Mn04_ PI 1 M H2SO4 in Jones Reduclor +0 05V(V2+ -V3+) <br /> 4.0 44V(V3+ _V5+) <br /> + I 1V(V4+ --V5+) <br />' Zn2+ K4Fe(CN)G PI pH 2-3, Add 3 4 drops 11/6 <br /> K3Fe(CN)6 <br /> TWO 5.3 Tilralions will,Melal Eleclmdes <br /> Specific Applications - Water pollution <br /> Applications for ORP measurement are not as - Reduction of chromate wastes <br /> E widespread as for pH, but several reasonably standard <br /> applications exist where ORP measurement and 1 Oxidation of Cyanide wastes <br /> control can be very useful Some of these While metal-plating and metal-treating industries <br /> E applications, Include produce the largest amount of cyanide waste. other <br /> - Oxidation of cyanide and chromate wastes industries use cyanide compounds as intermediates <br /> - Bleaching of pulp Oxidation converts the toxic cyanides to harmless <br /> - Manufacture of bleach compounds Typically, chlorine gas Is the oxidant <br /> EThe process Is usually carried out In two steps <br /> - Oxidation to cyanate Ion OCN <br /> E - Further oxidation to carbon dioxide and nitrogen <br /> In the first step caustic or time is added to make <br /> • the cyanide-bearing waste alkaline to a pH of 9 to 10 <br /> E <br /> E <br />