Liquid oxygen, blue color

Oxygen (OJ in a magnetic field. The liquid oxygen, which is blue, is attracted into a magnetic field between the poles of an electromagnet. Both the paramagnetism and the blue color are due to the unpaired electrons in the 02 molecule. 

O2 is a colorless, odorless, and tasteless gas imder normal conditions. Its content in the atmospheric air is 20.94% by volume or 20% by weight. The density of pure oxygen is 1.429 g dm at 273 K and 1.0 atm, which is slightly heavier than air. When cooled below its boiling point (-183 °C), O2 becomes a pale blue liquid when cooled below its melting point ( 218 °C), the liquid solidifies, retaining its color. The heat of vaporization is 3.4099 kJ mol and the heat of fusion is 0.22259 kJ mol . Liquid oxygen is potentially hazardous about flames and sparks in the presence of combustible materials. It can be separated from air by fractionated liquefaction and distillation. 

C) in the fractional distillation of liquid air. Liquid nitrogen and liquid oxygen also differ in their colors, colorless and pale blue, respectively. Oxygen has a small but significant solubility... 

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