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- 3: The Properties of Oxygen Gas (Experiment)
- Oxygen - O
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- 4: The Properties of Oxygen Gas (Experiment)
3: The Properties of Oxygen Gas (Experiment)
Oxygen O , nonmetallic chemical element of Group 16 VIa, or the oxygen group of the periodic table. Oxygen is a colourless, odourless, tasteless gas essential to living organisms, being taken up by animals, which convert it to carbon dioxide; plants, in turn, utilize carbon dioxide as a source of carbon and return the oxygen to the atmosphere.
Oxygen forms compounds by reaction with practically any other element, as well as by reactions that displace elements from their combinations with each other; in many cases, these processes are accompanied by the evolution of heat and light and in such cases are called combustions. Its most important compound is water.
Oxygen was discovered about by a Swedish chemist, Carl Wilhelm Scheele , who obtained it by heating potassium nitrate , mercuric oxide , and many other substances.
An English chemist, Joseph Priestley , independently discovered oxygen in by the thermal decomposition of mercuric oxide and published his findings the same year, three years before Scheele published. The proportion of oxygen by volume in the atmosphere is 21 percent and by weight in seawater is 89 percent. In rocks, it is combined with metals and nonmetals in the form of oxides that are acidic such as those of sulfur , carbon, aluminum , and phosphorus or basic such as those of calcium , magnesium , and iron and as saltlike compounds that may be regarded as formed from the acidic and basic oxides, as sulfates, carbonates, silicates, aluminates, and phosphates.
Plentiful as they are, these solid compounds are not useful as sources of oxygen, because separation of the element from its tight combinations with the metal atoms is too expensive. Pure oxygen is 1. During respiration, animals and some bacteria take oxygen from the atmosphere and return to it carbon dioxide, whereas by photosynthesis , green plants assimilate carbon dioxide in the presence of sunlight and evolve free oxygen.
Almost all the free oxygen in the atmosphere is due to photosynthesis. Dissolved oxygen is essential for the respiration of fish and other marine life. Natural oxygen is a mixture of three stable isotopes: oxygen Several artificially prepared radioactive isotopes are known. The longest-lived, oxygen second half-life , has been used to study respiration in mammals.
Oxygen has two allotropic forms, diatomic O 2 and triatomic O 3 , ozone. The properties of the diatomic form suggest that six electrons bond the atoms and two electrons remain unpaired, accounting for the paramagnetism of oxygen. The three atoms in the ozone molecule do not lie along a straight line. The process, as written, is endothermic energy must be provided to make it proceed ; conversion of ozone back into diatomic oxygen is promoted by the presence of transition metals or their oxides. The pungent odour of ozone is noticeable in confined areas in which there is sparking of electrical equipment, as in generator rooms.
Ozone is light blue; its density is 1. Ozone is a powerful oxidizing agent, capable of converting sulfur dioxide to sulfur trioxide, sulfides to sulfates, iodides to iodine providing an analytical method for its estimation , and many organic compounds to oxygenated derivatives such as aldehydes and acids.
The conversion by ozone of hydrocarbons from automotive exhaust gases to these acids and aldehydes contributes to the irritating nature of smog. Commercially, ozone has been used as a chemical reagent, as a disinfectant, in sewage treatment , water purification , and bleaching textiles. Production methods chosen for oxygen depend upon the quantity of the element desired. Laboratory procedures include the following:.
Thermal decomposition of certain salts, such as potassium chlorate or potassium nitrate:. The decomposition of potassium chlorate is catalyzed by oxides of transition metals; manganese dioxide pyrolusite, MnO 2 is frequently used. Scheele and Priestley used mercury II oxide in their preparations of oxygen. Thermal decomposition of metal peroxides or of hydrogen peroxide:.
An early commercial procedure for isolating oxygen from the atmosphere or for manufacture of hydrogen peroxide depended on the formation of barium peroxide from the oxide as shown in the equations. Electrolysis of water containing small proportions of salts or acids to allow conduction of the electric current:. When required in tonnage quantities, oxygen is prepared by the fractional distillation of liquid air. Of the main components of air, oxygen has the highest boiling point and therefore is less volatile than nitrogen and argon.
The process takes advantage of the fact that when a compressed gas is allowed to expand, it cools. Multiple fractionations will produce a product pure enough The treatment of sewage by oxygen holds promise for more efficient treatment of liquid effluents than other chemical processes.
Incineration of wastes in closed systems using pure oxygen has become important. The so-called LOX of rocket oxidizer fuels is liquid oxygen; the consumption of LOX depends upon the activity of space programs. Pure oxygen is used in submarines and diving bells. Commercial oxygen or oxygen-enriched air has replaced ordinary air in the chemical industry for the manufacture of such oxidation-controlled chemicals as acetylene , ethylene oxide, and methanol.
Medical applications of oxygen include use in oxygen tents, inhalators, and pediatric incubators. Oxygen-enriched gaseous anesthetics ensure life support during general anesthesia. Oxygen is significant in a number of industries that use kilns. The large values of the electronegativity and the electron affinity of oxygen are typical of elements that show only nonmetallic behaviour.
In all of its compounds, oxygen assumes a negative oxidation state as is expected from the two half-filled outer orbitals. This property of accepting electrons by complete or partial transfer defines an oxidizing agent.
When such an agent reacts with an electron-donating substance, its own oxidation state is lowered. As described in the section on allotropy , oxygen forms the diatomic species, O 2 , under normal conditions and, as well, the triatomic species ozone, O 3. There is some evidence for a very unstable tetratomic species, O 4. In the molecular diatomic form there are two unpaired electrons that lie in antibonding orbitals.
The paramagnetic behaviour of oxygen confirms the presence of such electrons. The molecular species, O 2 , is not especially reactive at normal ambient temperatures and pressures. The atomic species, O, is far more reactive.
It forms a large range of covalently bonded compounds, among which are oxides of nonmetals, such as water H 2 O , sulfur dioxide SO 2 , and carbon dioxide CO 2 ; organic compounds such as alcohols, aldehydes, and carboxylic acids; common acids such as sulfuric H 2 SO 4 , carbonic H 2 CO 3 , and nitric HNO 3 ; and corresponding salts, such as sodium sulfate Na 2 SO 4 , sodium carbonate Na 2 CO 3 , and sodium nitrate NaNO 3.
Oxygen is present as the oxide ion, O 2 - , in the crystalline structure of solid metallic oxides such as calcium oxide, CaO. Metallic superoxides, such as potassium superoxide, KO 2 , contain the O 2 - ion, whereas metallic peroxides, such as barium peroxide, BaO 2 , contain the O 2 2- ion.
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Oxygen - O
Oxygen O , nonmetallic chemical element of Group 16 VIa, or the oxygen group of the periodic table. Oxygen is a colourless, odourless, tasteless gas essential to living organisms, being taken up by animals, which convert it to carbon dioxide; plants, in turn, utilize carbon dioxide as a source of carbon and return the oxygen to the atmosphere. Oxygen forms compounds by reaction with practically any other element, as well as by reactions that displace elements from their combinations with each other; in many cases, these processes are accompanied by the evolution of heat and light and in such cases are called combustions. Its most important compound is water. Oxygen was discovered about by a Swedish chemist, Carl Wilhelm Scheele , who obtained it by heating potassium nitrate , mercuric oxide , and many other substances.
Where is this substance collected? 4) Two notable physical properties of oxygen are its low solubility in water and a density greater than air. a. Which one of.
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It is a member of the chalcogen group in the periodic table , a highly reactive nonmetal , and an oxidizing agent that readily forms oxides with most elements as well as with other compounds. After hydrogen and helium , oxygen is the third- most abundant element in the universe by mass. At standard temperature and pressure , two atoms of the element bind to form dioxygen , a colorless and odorless diatomic gas with the formula O 2.
4: The Properties of Oxygen Gas (Experiment)
Oxygen is one of the most abundant elements on this planet. Oxygen exhibits many unique physical and chemical properties. For example, oxygen is a colorless and odorless gas, with a density greater than that of air, and a very low solubility in water. In fact, the latter two properties greatly facilitate the collection of oxygen in this lab. Among the unique chemical properties of oxygen are its ability to support respiration in plants and animals, and its ability to support combustion.
What are the Properties of Oxygen? Definition of Oxygen What is the definition of Oxygen? It is a colorless, tasteless, odourless gaseous element that constitutes 21 percent of the atmosphere and is found in water, in most rocks and minerals, and in numerous organic compounds.
Oxygen is the first element in Group 16 VIA of the periodic table. The periodic table is a chart that shows how chemical elements are related to each other. The elements in Group 16 are said to belong to the chalcogen family. Other elements in this group include sulfur, selenium, tellurium, and polonium. The name chalcogen comes from the Greek word chalkos, meaning "ore. Oxygen is by far the most abundant element in the Earth's crust. Nearly half of all the atoms in the earth are oxygen atoms.
Department of Physical Sciences Kingsborough Community College The City collect molecular oxygen and demonstrate its reactivity with several chemical.
Allotropes Some elements exist in several different structural forms, called allotropes. Each allotrope has different physical properties. For more information on the Visual Elements image see the Uses and properties section below. Group A vertical column in the periodic table. Members of a group typically have similar properties and electron configurations in their outer shell. Period A horizontal row in the periodic table. The atomic number of each element increases by one, reading from left to right.
Gaseous chemical element, symbol: O, atomic number: 8 and atomic weight 15, Nearly one fifth in volume of the air is oxygen. Non-combined gaseous oxygen normally exists in form of diatomic molecules, O 2 , but it also exists in triatomic form, O 3 , named ozone. In normal conditions oxygen is a colourless, odourless and insipid gas; it condensates in a light blue liquid. Liquid oxygen is also slightly paramagnetic. Oxygen is reactive and will form oxides with all other elements except helium, neon, argon and krypton.
Oxygen is an important part of the atmosphere and is necessary to sustain terrestrial life. Because it comprises most of the mass in water, it also comprises most of the mass of living organisms. All major classes of structural molecules in living organisms, such as proteins, carbohydrates, and fats, contain oxygen, as do the major inorganic compounds that comprise animal shells, teeth, and bone. Elemental oxygen O 2 is produced by cyanobacteria, algae, and plants through the process of photosynthesis, and is used in cellular respiration by most living organisms on earth. Oxygen is toxic to obligate anaerobic organisms organisms which need a lack of oxygen for survival , which were the dominant form of early life on Earth, until O 2 began to accumulate in the atmosphere.
Затем Сьюзан сунула ноги в туфли и последовала за коммандером. - Какого черта ему здесь надо? - спросил Стратмор, как только они с Сьюзан оказались за дверью Третьего узла.