Nitrogen is one the most inert chemicals after the noble gases, which makes it a great environment for the performance of limited chemical reactions.8,9,14,15 There is no surprise that nitrogen is a great choice because of its high dissociation energy, high ionization energy, and the inability to access its highest vacant molecular orbitals.15 Molecular dinitrogen is a tightly wound nonpolar molecule in character with σ and π electrons.14 The inertness of molecular dinitrogen makes practicable activation a challenge for chemists, but nature can do this process easily.10,14 Nitrogen is not only an important element in the area scientific research, but biological processes also have a much desired need and use for nitrogen.15
Biological systems use nitrogen for their own life support processes and because nitrogen is the controlling factor in protein synthesis. Reduced nitrogen in the biosphere is required in order to perform the needed protein synthesis.8,9,15 The term of nitrogen fixation is no longer solely limited to biological systems and can now be defined more generally as the reduction of molecular dinitrogen to ammonia.15 Nitrogen fixation in organisms began to appear late in evolutionary development because it was thought that the earth had possessed ammonia as a main aspect and component in the atmosphere.1,15 Once the natural occurring supply had diminished and sufficient nitrogen appeared, the systems were required to evolve and adapt in order to continue getting the needed ammonia for survival.1,8,9,15 Reduction of dinitrogen is a key reaction in nature because nitrogen is an important element, but molecular dinitrogen alone is in an inaccessible form for most living organisms to use practically.11 Nitrog...
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... Sivasankar, C.; Baskaran, S.; Tamizmani, M.; Ramakrishna, K. Lessons learned and lessons to be learned for developing homogeneous transition metal complexes catalyzed reduction of N2 to ammonia. Journal of Organometallic Chemistry 2014, 752, 44-58.
(17) Szigethy, G.; Heyduk, A. F. Steric and Electronic Consequences of Flexibility in a Tetradentate Redox-Active Ligand: Ti(IV) and Zr(IV) Complexes. Inorg. Chem. 2011, 50, 125-135.
(18) Tsvetkov, N. P.; Chen, C.; Andino, J. G.; Lord, R. L.; Pink, M.; Buell, R. W.; Caulton, K. G. Synthesis and Oxidative Reactivity of 2,2 '-Pyridylpyrrolide Complexes of Ni(II). Inorg. Chem. 2013, 52, 9511-9521.
(19) Van Tamelen, E. E.; Fechter, R. B.; Schneller, S. W.; Boche, G.; Greeley, R. H.; Akermark, B. Titanium(II) in the fixation-reduction of molecular nitrogen under mild conditions. J. Am. Chem. Soc. 1969, 91, 1551-1552.
It is shown that the black color or the strain STM 5480 is more efficient in nitrogen fixing than the white color or STM 5472 strain in the singe-inoculation assay. It is also seen that the biomass...
This experiment focuses on the SN2 nucleophile substitution reaction of converting 1-butanol (an alcohol) to 1-bromobutane (an alkyl halide). There are two types of substitution mechanisms that could be used, SN1 and SN2. SN1 mechanisms take place in two steps. The first rate-determining step is the ionization of the molecule. This mechanism is called unimolecular because its rate is only dependent on the concentration of the leaving group. The second step is the fast, exothermic nucleophile addition. In an SN2 reaction the leaving group leaves as the nucleophile attacks all in one step. Because this happens at one time, the nucleophile must attack from the opposite side from which the leaving group is leaving. For this reason, SN2 reactions
There is an overwhelming use of catalysts - a substance that changes the rate of reaction without being consumed by the reaction itself- in various industrial processes. According to certain estimates [cite-wiki10] around 90% of all “commercially produced chemical products involve catalysts at some stage in the process of their manufacture.” Chemical products worth $900 billion were generated by catalytic processes worldwide in 2005 [cite – wiki11]. The close affiliation of the catalysts and the process of catalysis to a variety of industries and the proximity of these industries with consumers raise questions regarding the application of catalysts and their effects on products.
Nitrogen fertilizers: firstly nitrogen is found in the air, so air is pumped into a large vessel. The air is warmed and oxygen is removed becoming steam. This leaves hydrogen, nitrogen and carbon dioxide. To remove the carbon dioxide an electric current is introduced into the system. And finally remains ammonia. Ammonia is further processed adding air to the solution and making nitric acid. In conclusion when ammonia and nitric acid are combined is made ammonium nitrate, the component used as fertilizers.
This chemistry book report is focus on a book called “Napoleon's buttons: How 17 molecules changed history” by Penny Le Couteur and Jay Burreson. The publisher of this book is Tarcher Putnam, the book was published in Canada on 2003 with 17 chapters (hey the number match the title of the book!) and a total of 378 pages. The genre of this book is nonfiction. “Napoleon's Buttons” contain a fascinating story of seventeen groups of molecules that have greatly changed the course of history and continuing affect the world we live in today. It also reveal the astonishing chemical connection among some unrelated events, for example: Chemistry caused New Amsterdamers to be renamed New Yorkers and one little accident of detonating cotton apron in a minor housekeeping mishap lead to the development of modern explosives and the founding of the movie industry.
Varying the n value carries out the experiment. Absorbencies of each of the ZLn complexes are obtained. The sum of the concentrations of the metal, Z, and the ligand, L, are kept equal. With the ratio of the ligand to the metal in the solution with the maximum absorbance for the ZLn complex, the value of n can be determined as well as the composition of ZLn.
Predictions may be made about the suitability of possible catalysts by assuming that the mechanism of catalysis consists of two stages, either of which can be first:
Thickett, Geoffrey. Chemistry 2: HSC course. N/A ed. Vol. 1. Milton: John Wiley & Sons Australia, 2006. 94-108. 1 vols. Print.
David and John Free. (26 Nov 2006). MadSci Network: Chemistry. Retrieved on March 6, 2011, from http://www.madsci.org/posts/archives/2007-02/1171045656.Ch.r.html
23. S. Alwarappan, S. Boyapalle, A. Kumar, C.-Z. Li and S. Mohapatra, J. Phys. Chem. C, 2012, 116, 6556–6559
Nitrogen is vital in our world. About four fifths of the air we breathe is nitrogen. Most importantly, nitrogen is one of the most important elements because it is the base of the food web and it is involved in a fundamental cycle. Free nitrogen in the air is absorbed by plants and converted to plant proteins. It is then eaten by animals that convert it to animal proteins and return it to the soil as nitrogen waste. Then bacterial action causes the nitrogen compounds to become free nitrogen again. Thus, plants need nitrogen to survive, the animals need the plant proteins to survive, and we in turn need animals and plants to survive.
Plontke, R. (2003, March 13). Chemnitz UT. TU Chemnitz: - Technische Universität Chemnitz. Retrieved April 1, 2014, from http://www.tu-chemnitz.de/en/
Ionic compounds, when in the solid state, can be described as ionic lattices whose shapes are dictated by the need to place oppositely charged ions close to each other and similarly charged ions as far apart as possible. Though there is some structural diversity in ionic compounds, covalent compounds present us with a world of structural possibilities. From simple linear molecules like H2 to complex chains of atoms like butane (CH3CH2CH2CH3), covalent molecules can take on many shapes. To help decide which shape a polyatomic molecule might prefer we will use Valence Shell Electron Pair Repulsion theory (VSEPR). VSEPR states that electrons like to stay as far away from one another as possible to provide the lowest energy (i.e. most stable) structure for any bonding arrangement. In this way, VSEPR is a powerful tool for predicting the geometries of covalent molecules.
Nitrogen is used by plants in order to synthesize protein peptide bonds and for cell growth. Not only is this nutrient required in the largest quantity by plants, but it is also the most frequently limiting factor when it comes to productivity in crops. Plants cannot use nitrogen in the air and in the soil system it is lost easily. Because of this plants are forced to obtain nitrogen in the form of nitrate and ammonium from the soil. Too much nitrate can cause a negative effect on the plant including nitrate toxicity. High levels of nitrate are not only bad for plants but can also be dangerous to animals or humans in their presence. Here I discuss the scientific evidence of the effects of nitrate accumulation on plants and the environment and argue that too much nitrate accumulation can be harmful to its surroundings.
...eochemical cycles. By increasing the amount of crops that are removed from the soil and the subsequent soil erosion, phosphorus levels in the soil have dropped. The phosphorus lost from the soils travels to aquatic ecosystems which then can cause massive algal blooms. The increased use of nitrogen based fertilizers has also altered that cycle. The fertilizers add high levels of nitrates to the soil, and in natural ecosystems, nitrates will undergo denitrification and be returned as atmospheric nitrogen. This is not the case because the nitrate levels exceed the levels of denitrification that bacteria can handle. Additionally, much of the denitrifying bacteria is found in marshes and wetlands, which are currently being destroyed at incredible rates. In some areas, the excess nitrate has made it into the ground water system and contaminated the drinking water system.