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Oxidation & Electrons | Appearance & Characteristics Reactions | Compounds | Radius | Conductivity Abundance & Isotopes 
Oxygen cylinders. |
General:
| Name: Oxygen | Symbol: O |
| Type: Non-Metal, Chalcogen | Atomic weight: 15.9994 |
| Density @ 293 K: 0.001429 g/cm3 | Atomic volume: 14.0 cm3/mol |
| Discovered: Oxygen was discovered in 1774 by J. Priestley in England and independently by C. W. Scheele in Sweden. The word oxygen is derived from the Greek words 'oxys' meaning acid and 'genes' meaning forming. | |
States
| State (s, l, g): gas | |
| Melting point: 54.8 K (-218.3 oC) | Boiling point: 90.2 K (-182.9 oC) |
Energies
| Specific heat capacity: 0.918 J g-1 K-1 | Heat of atomization: 249 kJ mol-1 |
| Heat of fusion: 0.444 kJ mol-1 of O2 | Heat of vaporization (sublimation): 6.82 kJ mol-1 of O2 |
| 1st ionization energy: 1313.9 kJ mol-1 | 2nd ionization energy: 3388.2 kJ mol-1 |
| 3rd ionization energy: 5300.3 kJ mol-1 | Electron affinity: 140.97875 kJ mol-1 |
Oxidation & Electrons
| Shells: 2, 6 | Electron configuration: [He] 2s2 2p4 |
| Minimum oxidation number: -2 | Maximum oxidation number: 25 |
| Min. common oxidation no.: -2 | Max. common oxidation no.: 0 |
| Electronegativity (Pauling Scale): 3.44 | Polarizability volume: 0.793 Å3 |
Appearance & Characteristics
| Structure: | Color: Colorless |
| Harmful effects: O2 is non-toxic under normal conditions. However, exposure to oxygen at higher than normal pressures, e.g. scuba divers, can lead to convulsions. Ozone (O3) is toxic and if inhaled can damage the lungs. | Hardness: mohs |
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Characteristics: Oxygen in its common form (O2) is a colorless, odorless and tasteless diatomic gas. Oxygen is extremely reactive and forms oxides with nearly all other elements except noble gases. Earth's atmosphere at first contained no free oxygen. It only contains free oxygen now because green plants - not initially present on Earth - produce it during photosynthesis. If green plants were to disappear, all the free oxygen in Earth's atmosphere would react over a period of time and the atmosphere would once again contain no free oxygen. If we discover any other planets with atmospheres rich in oxygen, we will be able to infer that life is almost certainly present on these planets. Liquid and solid oxygen are pale blue and are strongly paramagnetic. Ozone (O3), another form (allotrope) of oxygen, occurs naturally in the Earth's upper atmosphere. The reaction with oxygen is one of the critera we use to distinguish between metals - these form basic oxides - and non-metals - these form acidic oxides. Uses: Oxygen is used in oxyacetylene welding and in steel manufacture. It is also used in manufacturing methanol and ethylene oxide and as an oxidant for rocket fuel. Plants and animals rely on oxygen for respiration. Oxygen is frequently used to help breathing in patients with respiratory ailments. Naturally occurring ozone in the upper atmosphere shields the earth from ultraviolet radiation. |
Reactions
| Reaction with air: none | Reaction with 6 M HCl: none |
| Reaction with 15 M HNO3: none | Reaction with 6 M NaOH: none |
Compounds
| Oxide(s): O2, O3 | Chloride(s): Cl2O, ClO2 |
| Hydride(s): H2O |
Radius
| Atomic radius: 60 pm | Ionic radius (1+ ion): pm |
| Ionic radius (2+ ion): pm | Ionic radius (3+ ion): pm |
| Ionic radius (2- ion): 126 pm | Ionic radius (1- ion): pm |
Conductivity
| Thermal conductivity: 0.02583 W m-1 K-1 | Electrical conductivity: S cm-1 |
Abundance & Isotopes
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Laboratory electrolysis of water. Electrical energy is used to split water. Watch out for the different ways the two gases are collected. |
Abundance earth's crust: 46 % by weight, 60 % by moles
Abundance solar system: 9,000 ppm by weight, 700 ppm by moles Cost, pure: 0.3 $/100g Cost, bulk: 0.02 $/100g Source: Oxygen is obtained commercially from liquefied air separation plants. It can be prepared in the laboratory by electrolysis of water. Isotopes: 13 whose half-lives are known, with mass numbers 12 to 24. Of these, three are stable: 16O, 17O and 18O. |
