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(a) Why do we paint objects made up of iron?
(b) Why is Nitrogen gas filled in food packets containing oil and fats?
(C) Which processes are responsible for (a) and (b)?
Answers
Answer:
a. because if we not paint iron then it forms rust
b.the oxygen is highly reactive so it like to combines with other molecules which results spoiling or losing it freshness
c.a forms rust and b. forms fungi.....
Answer:
a) Unprotected iron rusts away much faster in such waters than in common air ; but exposed to the action of the ordinary substances, to be found in all places where structures o. ... Another class of substances are paints, tar, linseed oil, etc., which form coatings upon the surface of iron and thus isolate it from oxygen.
b) Most commonly it is combined with nitrogen at 30% to 40% to inhibit anaerobic spoilage mechanisms. Due to its relatively high solubility, it easily dissolves into the moisture and fat of food products.
c)The nitrogen cycle describes the conversion of nitrogen between different chemical forms. The majority of the earth’s atmosphere (about 78%) is composed of atmospheric nitrogen, but it is not in a form that is usable to living things. Complex species interactions allow organisms to convert nitrogen to usable forms and exchange it between themselves. Nitrogen is essential for the formation of amino acids and nucleotides. It is essential for all living things.
Fixation: In order for organisms to use atmospheric nitrogen (N2), it must be “fixed” or converted into ammonia (NH3). This can happen occasionally through a lightning strike, but the bulk of nitrogen fixation is done by free living or symbiotic bacteria. These bacteria have the nitrogenase enzyme that combines gaseous nitrogen with hydrogen to produce ammonia. It is then further converted by the bacteria to make their own organic compounds. Some nitrogen fixing bacteria live in the root nodules of legumes where they produce ammonia in exchange for sugars. Today, about 30% of the total fixed nitrogen is manufactured in chemical plants for fertilizer.
Nitrificaton: Nitrification is the conversion of ammonia (NH3) to nitrate (NO3–). It is usually performed by soil living bacteria, such as nitrobacter. This is important because plants can assimilate nitrate into their tissues, and they rely on bacteria to convert it from ammonia to a usable form. Nitrification is performed mainly by the genus of bacteria, Nitrobacter.
Ammonification /Mineralization: In ammonification, bacteria or fungi convert the organic nitrogen from dead organisms back into ammonium (NH4+). Nitrification can also work on ammonium. It can either be cycled back into a plant usable form through nitrification or returned to the atmosphere through de-nitrification.
De-Nitrification: Nitrogen in its nitrate form (NO3–) is converted back into atmospheric nitrogen gas (N2) by bacterial species such as Pseudomonas and Clostridium, usually in anaerobic conditions. These bacteria use nitrate as an electron acceptor instead of oxygen during respiration.
ron (Fe) follows a geochemical cycle like many other nutrients. Iron is typically released into the soil or into the ocean through the weathering of rocks or through volcanic eruptions.
The Terrestrial Iron Cycle: In terrestrial ecosystems, plants first absorb iron through their roots from the soil. Iron is required to produce chlorophyl, and plants require sufficient iron to perform photosynthesis. Animals acquire iron when they consume plants, and iron is utilized by vertebrates in hemoglobin, the oxygen-binding protein found in red blood cells. Animals lacking in iron often become anemic and cannot transmit adequate oxygen. Bacteria then release iron back into the soil when they decompose animal tissue.
The Marine Iron Cycle: The oceanic iron cycle is similar to the terrestrial iron cycle, except that the primary producers that absorb iron are typically phytoplankton or cyanobacteria. Iron is then assimilated by consumers when they eat the bacteria or plankton. The role of iron in ocean ecosystems was first discovered when English biologist Joseph Hart noticed “desolate zones,” which are regions that lacked plankton but were rich in nutrients. He hypothesized that iron was the limiting nutrient in these areas. In the past three decades there has been research into using iron fertilization to promote alagal growth in the world’s oceans. Scientists hoped that by adding iron to ocean ecosystems, plants might grown and sequester atmospheric CO2. Iron fertilization was thought to be a possible method for removing the excess CO2 responsible for climate change. Thus far, the results of iron fertilization experiments have been mixed, and there is concern among scientists about the possible consequences of tampering nutrient cycles.