Sentence Examples

  • Towards the middle of the 18th century two new elements were isolated: cobalt by G.
  • Three characteristic oxides of cobalt are known, the monoxide, CoO, the sesquioxide, C0203, and tricobalt tetroxide, C0304; besides these there are probably oxides of composition Co02, Co 8 0 9, C0607 and C0405.
  • They are precipitated from their alkaline solutions as cobalt sulphide by sulphuretted hydrogen, but this precipitation is prevented by the presence of citric and tartaric acids; similarly the presence of ammonium salts hinders their precipitation by caustic alkalis.
  • Nickel and cobalt are also strongly magnetic, and in 1903 the interesting discovery was made by F.
  • Metallic cobalt may be obtained by reduction of the oxide or chloride in a current of hydrogen at a red heat, or by heating the oxalate, under a layer of powdered glass.