Oxygen, condensation

Oxygen condenses to a pale blue, mobile paramagnetic liquid (bp — 183.0°C at 1 atm). 

Over 4 billion years ago the heat from the sun was about 30% less powerful than it is today. A number of elements, including carbon and oxygen, condensed to form the earth and as the earth s crust cooled and hardened, hot gases from the interior were ejected including carbon dioxide. 

The induced bands mentioned are known from spectral studies with liquid, solid and compressed gaseous oxygen. Condensed oxygen is blue, because of the red 0-0 absorption bands near 760 and 630 nm, and their 1-0 counterparts, that is, because of interaction-induced absorption. 

Liquid Phase Condensed Oils (high P) (phenols, aromatics) Primary Liquids (low P, short x) (oxygenates) Condensible Tars (BTX, phenols, aromatics) ... 

The acetylene cylinder must be chained securely to the wall or laboratory bench. Work on a vacuum system requires a preliminary review of procedures and careful execution in order to avoid damage to the apparatus and possible injury from broken glass in addition, the liquid nitrogen used for cold traps must be handled properly (see Appendix C). Safety glasses must be worn. Acetylene is flammable no flames can be permitted in the synthesis area. Take great care not to allow oxygen condensation to occur in the presence of acetylene (potentially explosive). Carry out as many operations as possible in a fume hood. Dispose properly of excess CaC2. 

In the context of coal cleaning, oxygen is often considered unimportant because it is nonpolluting. But some consideration should be given to the effect of oxygen on the fate of its nitrogen and sulfur compatriots as well as its effect when water (a product of the combustion of hydrocarbons which also contain oxygen) condenses with other by-products on the cooler parts of combustion systems corrosive, aqueous acids can be the result. 

Fig. 3. Oxygen condensation rate in 0.312 ft tank at various tank pressures. 4 /

Oxygen is the most abundant element in the earth s mantle. It constitutes by weight 89% of water, 23% of air (21% by volume), and nearly 50% of the common minerals (silicates). The element consists of diatomic molecules, with the structure described below. It is a colorless, odorless gas, which is slightly soluble in water 1 liter of water at 0° dissolves 48.9 ml of oxygen gas at 1 atm pressure. Its density at 0°C and 1 atm is 1.429 g liter . Oxygen condenses to a pale blue liquid as its boiling point, — 183.0°C, and on further cooling freezes, at—218.4°C, to a pale blue crystalline solid. 

Glowing combustion and flame Combustion is the process of exothermic, self-catalyzed reaction involving either a condensed-phase or a gas-phased fuel, or both. The process is usually (but not necessarily) associated with oxidation of a fuel by atmospheric oxygen. Condensed-phase combustion is usually referred to as glowing combustion, while gas-phase combustion is referred to as aflame. 

---