title: Holmium(III) nitrate
text: # Holmium(III) nitrate
  
  Holmium (III) nitrate is an inorganic compound, a salt of holmium and nitric acid with the chemical formula $Ho(NO_3)_3.$ The compound forms yellowish crystals, dissolves in water, also forms crystalline hydrates.
  
  ## Synthesis
  
  Anhydrous salt is obtained by the action of nitrogen dioxide on holmium(III) oxide:
  
         ${\mathsf {2Ho_{2}O_{3}+9N_{2}O_{4}\ {\xrightarrow {150^{o}C}}\ 4Ho(NO_{3})_{3}+6NO}}$
  
  Effect of nitrogen dioxide on metallic holmium:
  
         ${\mathsf {Ho+3N_{2}O_{4}\ {\xrightarrow {200^{o}C}}\ Ho(NO_{3})_{3}+3NO}}$
  
  Reaction of holmium hydroxide and nitric acid:
  
         ${\mathsf {Ho(OH)_{3}+3NHO_{3}\ \xrightarrow {150^{o}C} \ Ho(NO_{3})_{3}+3H_{2}O}}$
  
  ## Physical properties
  
  Holmium(III) nitrate forms yellowish crystals.
  
  Forms a crystalline hydrate of the composition $Ho(NO_3)_3•5H_2O.$
  
  Soluble in water and ethanol.
  
  ## Chemical properties
  
  Hydrated holmitic nitrate thermally decomposes to form HoONO $_3$ and decomposes to holmium oxide upon subsequent heating.
  
  ## Application
  
  The compound is used for the production of ceramics and glass.
  
  Also used to produce metallic holmium and as a chemical reagent.
  
  