Calorimetric study on the decomposition of hydroxylamine in the presence of transition metals.
Hydroxylamine (HA), hydroxylamine chloride (HAC1), and hydroxylamine nitrate (HAN) were each mixed with aqueous solutions of Cr3+, Cr6+, Mn7+, Co2+, Co3+, and Cu2+, and their heat flow profiles were monitored by a small-scaled reaction calorimeter, SuperCRC. These mixing tests demonstrated that HA was less reactive than HACl and HAN with Mn7+ and Cr6+. Their UV-vis spectra confirmed that the substrates reacted when Mn7+ and Cr6+ were reduced. HA was more reactive with Cu2+ than HAC1 and HAN and exhibited the highest reactivity among the three substrates with regard to metals in the intermediate oxidation states: Cr3+, Co3+, and Co2+. During the reaction of HA and Co3+, an induction period was observed. All exothermic reactions were accompanied by precipitation or a change in the UV-vis spectra.
Kumasaki
Mieko
M
National Institute of Industrial Safety, 1-4-6 Umezono Kiyose, Tokyo 204-0024, Japan. miggy@anken.go.jp
D002151:Calorimetry / Q000379:methods*; D002857:Chromium / Q000737:chemistry; D003035:Cobalt / Q000737:chemistry; D003300:Copper / Q000737:chemistry; D005290:Ferric Compounds / Q000737:chemistry; D019811:Hydroxylamine / Q000737:chemistry*; D008274:Magnesium / Q000737:chemistry; D008670:Metals / Q000737:chemistry*; D028561:Transition Elements / Q000737:chemistry*
D005290:Ferric Compounds; D008670:Metals; D028561:Transition Elements; D002857:Chromium; D019811:Hydroxylamine; D003035:Cobalt; D003300:Copper; D008274:Magnesium