title: Holmium acetate
text: # Holmium acetate
  
  Holmium acetate is the acetate salt of holmium, with a chemical formula of $Ho(CH_3COO)_3.$
  
  ## Preparation
  
  Holmium acetate can be obtained by dissolving holmium carbonate in acetic acid:
  
      $Ho_2(CO_3)_3$ + 6 $CH_3COOH$ → 2 $(CH_3COO)_3Ho$ + 3 $H_2O$ + 3 $CO_2↑$
  
  Dissolving holmium oxide in acetic acid at a pH of 4 will form the tetrahydrate of holmium acetate $(Ho_2(CH_3COO)_6·4H_2O):$
  
      $Ho_2O_3$ + 6 $CH_3COOH$ → 2 $Ho(CH_3COO)_3$ + 3 $H_2O$
  
  ## Physical properties
  
  Holmium acetate's hemihepthydate decomposes at 105 °C, forming into a hemihydrate, further decomposing at 135 °C into an anhydride. Further adding heat will form $Ho(OH)(CH_3COO)_2,$ $HoO(CH_3COO)$ then $Ho_2O_2CO_3,$ forming holmium oxide at 590 °C.
  
  ## Applications
  
  Holmium acetate is used in the manufacture of ceramics, glass, phosphors, metal halide lamps, and as a dopant in garnet lasers. It is also used in nuclear reactors to keep the chain reaction in check.
  
  