Oxidation-reduction reactions violent

It reacts violently in halogen-exchange and oxidation-reduction reactions. Phosphorus trichloride... 

The base was being prepared by distilling a mixture of hydroxylamine hydrochloride and sodium hydroxide in methanol under reduced pressure, and a violent explosion occurred towards the end of distillation [1], probably owing to an increase in pressure above 53 mbar. It explodes when heated under atmospheric pressure [2], Traces of hydroxylamine remaining after reaction with acetonitrile to form acetamide oxime caused an explosion during evaporation of solvent. Traces can be removed by treatment with diacetyl monoxime and ammoniacal nickel sulfate, forming nickel dimethylglyoxime [3], An account of an extremely violent explosion towards the end of vacuum distillation had been published previously [4], Anhydrous hydroxylamine is usually stored at 10°C to prevent internal oxidation-reduction reactions which occur at ambient temperature [5], See other REDOX REACTIONS... 

Combustion is an oxidation-reduction reaction between a nonmetallic material and molecular oxygen. Combustion reactions are characteristically exothermic (energy releasing). A violent combustion reaction is the formation of water from hydrogen and oxygen. As discussed in Section 9.5, the energy from this reaction is used to power rockets into space. More common examples of combustion include the burning of wood and fossil fuels. The combustion of these and other carbon-based chemicals forms carbon dioxide and water. Consider, for example, the combustion of methane, the major component of natural gas ... 

When a beaker of hot nitric acid is poured on ordinary sugar, a violent oxidation-reduction reaction occurs. 

The sequence of reactions involved in the overall reduction of nitric acid is complex, but direct measurements confirm that the acid has a high oxidation/reduction potential, -940 mV (SHE), a high exchange current density, and a high limiting diffusion current density (Ref 38). The cathodic polarization curves for dilute and concentrated nitric acid in Fig. 5.42 show these thermodynamic and kinetic properties. Their position relative to the anodic curves indicate that all four metals should be passivated by concentrated nitric acid, and this is observed. In fact, iron appears almost inert in concentrated nitric acid with a corrosion rate of about 25 pm/year (1 mpy) (Ref 8). Slight dilution causes a violent iron reaction with corrosion rates >25 x 1()6 pm/year (106 mpy). Nickel also corrodes rapidly in the dilute acid. In contrast, both chromium and titanium are easily passivated in dilute nitric acid and corrode with low corrosion rates. 

A student, who should have mixed solutions of these two salts, mixed the solids and added water, which provoked a violent reaction. It is suggested that pupils should not be allowed access to solid, undiluted, oxidants and reductants at the same time. 

Owing to the very reactive nature of RuO relatively few solvents are suitable for its reactions. It is soluble in water to the extent of some 2% and is stable in such solutions, but reacts violently with diethyl ether, benzene and pyridine [236]. It has often been used catalytically in a biphasic system, with the co-oxidant in the aqueous layer. Under these circumstances the RuO formed from reduction of RuO by the substrate is re-oxidised at the organic - aqueous interface, so that oxidations with such systems can be much enhanced by stirring, shaking or sonication. In some cases (e.g. oxidation of aUcenes) it may be necessary to cool the reactants below room temperature, but in most cases ambient temperatures suffice, as indeed they do for the vast majority of organic oxidations catalysed by Ru complexes. 

Reduction of metal oxides by other metals (Figure 10.6, p. 154). Demonstrate the Thermit reaction and the reactions between the metals magnesium, zinc, iron and copper and their oxides. This will establish an order of reactivity for these metals. Some of these reactions are very violent so the use of small quantities and a rehearsal before the class demonstration are essential. R... 

Since dry acetonitrile is an effective solvent for many strongly oxidizing materials (e.g. XeFr) it was tested for use with the nickel fluorides, but was found to be too easily oxidized to be of value. The interaction with If-NiFa was violent even at —40 °C, but H- and P-NiFs interacted very slowly even at 20 °C, but with eventual reduction of the NiFs to NiFr. In the instance of the reaction with P-NiFs this released potassium fluoride, which provided a measure of the potassium content of that fluoride (approximately Ko.iNiFj). 

Numerous examples of homoleptic complexes in high or low formal oxidation states are known. In general, the high oxidation state complexes are best prepared by chemical or electrochemical oxidation of the normal oxidation state compounds, followed by further reaction in situ or precipitation with a suitable inert anion. In this respect, perchlorate is ideal as both oxidant and precipitant, but the complexes obtained are frequently violently explosive. Similarly, the low oxidation state complexes are best obtained by chemical or electrochemical reduction of available compounds (or normal oxidation salts in the presence of an excess of bpy). Commonly used reductants have included dissolving metals (zinc, sodium, lithium, magnesium) and the complexes Li(bpy) and Li2(bpy). Isolated examples are known of the synthesis of low oxidation state complexes by reaction of M(0) complexes with bpy or by metal vapor synthesis. 

Sodium metal and chlorine gas react violently to form sodium chloride. Oxidation and reduction happen together in this reaction. 

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