Nitrogen Quotes (10 quotes)
Air is nothing but a mixture of a variety of gasses. The air in the atmosphere consists of nitrogen, oxygen, which is the life-sustaining substance for animals and. Oxygen and water: reaction mechanisms, environmental impact and health effects. Request a quote · Phone: +31 [email protected] In air with a normal composition the oxygen partial pressure is atm. . reduction compound that may be applied instead of hydrogen: O2 + N2H4 -> N2 + 2 H2O. The earth is bountiful, and where her bounty fails, nitrogen drawn from the air oxygen and nitrogen struggle for billions of years to organise themselves into a The more the relationships of the nitrogen-rich substances to the cell nucleus.
Water presses present gases closer together, so that it can take up enough space. When the amount of water in the air is very low, air is called 'dry'. The weight of 22,4 dm3 of dry air is 28,96 grams. When the air contains sufficient amounts of water it is called humid.Extraction of oxygen and nitrogen from liquid air - Chemistry for All - The Fuse School
Humid air is lighter less dense than dry air. Apart from the elements that have been summed up earlier, other elements are also present in air. However, the percentages of these elements are very low. Aerosols can be found in air. These are dust particles that are blown off the earth's surface by wind, or emitted during volcanic activity. When burning processes take place, ashes and grime particles also end up in the air.
The composition of air varies greatly with height. Over ninety kilometres above the earths' surface oxygen molecules fall apart and only oxygen atoms are left. Over one hundred kilometres above the earths' surface, nitrogen molecules also decompose.
At this height the air does not have the composition we know. The atmosphere is completely different there. All chemical elements can be found in several different states phases. One of these phases is the gaseous phase. Apart from gaseous an element can also be solid or liquid. Water is called ice when it is solid, it is wet when it is liquid, and when it is gaseous it exists merely as gas or steam. When temperatures rise, the molecules of a substance part, causing the substance to become gaseous and less visible.
This phase change causes air to be invisible. When temperatures fall air molecules are closer together and a substance eventually becomes solid. The temperatures at which each 'phase-change' takes place differs for each substance.
Where on earth do we find air? We can state that air can be found everywhere on earth exept where there is water. Air is even located in the surface layer of the earth; in the soil.
Oxygen Quotes (71 quotes)
Air is not only located on earth, it is also located around the earth in an air layer called the atmosphere. The atmosphere can be divided up in separate layers depending on temperature and height.
These lines are not clearly separated by straight borders; they gradually overflow one another. The first layer of air, which is located closest to the earth is called the troposphere. This layer is 11 kilometres in height. When moving up in the troposphere temperatures fall six or seven degrees per kilometre. Consequentially the weather on earth is mainly determined by circumstances within the troposphere.
The upper layer of the troposphere is called tropopause. Near the Antarctic, the tropopause layer is located eight to ten kilometres above earth. However, at the equator the tropopause layer is located at seventeen to eighteen kilometres above earth. The second layer of air above the troposphere is called stratosphere. Temperatures stop decreasing in the lower part of this layer. The temperature is around degrees Celsius here. In the higher stratosphere temperatures are rising to zero degrees Celsius at forty-seven kilometres above earth.
Within the stratosphere solar radiation creates ozone O3 from oxygen O2between twenty and forty kilometres above the earth's surface. This reaction causes this part of the stratosphere to be referred to as 'ozone-sphere'. It is water soluble and functions as an oxidator: This is principally a biological process.
Each individual compound has a reaction mechanism that can be described by means of an electron balance.
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Examples are given below H2O is excluded: The oxygen atom is very reactive and forms oxides with virtually all other elements, with the exception of heliumneonargon and krypton. There are also a large amounts of compounds that react with water. In air with a normal composition the oxygen partial pressure is 0. This results in dissolution of Oxygen solubility is strongly temperature dependent and decreases at higher temperatures.
Oxygen solubility is negatively correlated with the amount of dissolved solids. The saturation constant in rivers and lakes in mountainous areas is usually lower than in lowlands, because it is pressure dependent.
Why is oxygen present in water? As was described earlier, oxygen dissolves naturally when water comes in contact with air. Oxygen is also applied commercially. For industrial purposes the element is extracted from air by about million tons annually.
In chemical industries a reaction of oxygen and ethylene is applied, and the resulting ethylene oxide is applied as an antifreeze and polyester. Oxygen is highly reactive, and can therefore be applied to break down hazardous substances.
It may also be applied as a bleach. Oxygen in ozone compounds is applied for drinking water disinfection. Waters are not contaminated by oxygen when it is applied industrially. What are the environmental effects of oxygen in water?
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Oxygen oxidizes other substances. This occurs for example during fires, but also within organisms, during bacterial destruction and during metal conversion. All plants and animals require oxygen for breathing.
Oxygen is very essential, because it is a part of the DNA and virtually all other compounds that are biologically significant. In the lungs oxygen is bound to iron atoms; central elements of haemoglobin.
A total of cm3 of oxygen can dissolve in blood by this mechanism, an amount that clearly exceeds the water soluble amount. Together with energy reserves oxygen causes muscle activity and heat production. This process releases carbon dioxidewhich is emitted and subsequently taken up by plants. Plants produce additional oxygen during photosynthesis.
Plants contain between 4. Dissolved oxygen is an important determinant for stability of waters and survival of water organisms. Micro organisms may decompose organic substances in water by means of oxygen. Organic pollutants may negatively influence water organisms, because they decrease BOD. Thermal pollution causes the same problem, because oxygen solubility is lower in warmer water. This may be a consequence of cooling water discharge on surface waters.
In eutrophic lakes and relatively enclosed sea areas, oxygen concentrations decrease strongly with depth. In some cases conditions may even be anaerobic.
Natural examples of influences of temperature on oxygen concentrations in water and environmental impact are seasonal temperature changes in lakes. In winter the water has the same temperature and oxygen concentration everywhere. In summer water in surface layers in warmer than deeper water, resulting in lower oxygen solubility. Algae and plants in the surface layers work oppositely. They produce a high amount of oxygen at high temperatures, causing the water to become oxygen saturated.
These plants die off pretty quickly, and are decomposed by micro organisms applying oxygen, which is now abundant in surface layers of the water source. However, organic matter often settles and remains on the bottom of a water body as sediment.
This may cause oxygen deficits from decomposition. When an ecological equilibrium is established in lakes, these problems may be solved. However, when discharge, over fertilization, etc. As pure O2 oxygen is generally not released in amounts that would be hazardous to any aerobic organism. Theoretically, such concentrations are obtainable, and the critical partial pressure differs per species.
Oxygen atoms can be found in a number of toxic organic and inorganic compounds.