Nitrate release rates

Fig. 6.18 Regional distribution of benthic nitrate (a) and phosphate (b) release rates in the South Atlantic below 1,000 m water depth (from Hensen et al. 1998).

Dry aluminium nitrate does not attack aluminium. Its solutions have a slight action at room temperature the dissolution rate is in the order of 0.4 mm per year at 20 °C. At higher temperatures, the hydrolysis of aluminium nitrate releases nitric acid, which, due to its low concentration, may attack aluminium. The dissolution rate is 10 times higher at 50 °C than at 20 °C, and in addition, pitting corrosion is observed. Aluminium nitrate can be produced (from calcium nitrate and aluminium sulphate), stored and transported in aluminium equipment. 

A silicon atom might be expected to release electrons inductively, but because of empty 7-orbitals shows the overall character ( + 7 —717). Nitration of trimethylsilylbenzene with nitric acid in acetic anhydride at —10 to o °C gives 25-5,39-8,30-2 and 6-8 %, respectively, of 0-, m-, and /)-nitro-trimethylsilylbenzene and nitrobenzene, with a rate of reaction relative to that of benzene of about 1-5. The figures give no indication of an important conjugative effect. 

A methyl group is an electron releasing substituent and activates all of the ring carbons of toluene toward electrophilic attack The ortho and para positions are activated more than the meta positions The relative rates of attack at the various positions m toluene compared with a single position m benzene are as follows (for nitration at 25°C)... 

A lire disaster costing 67 million occurred in Texas City, Texas, on the SS Grandcamp (16 April 1987) due to spontaneous ignition of stored fertilizer in the ship s hold. A release of steam from an engine leak caused the atmosphere of the ammonium nitrate fertilizer to be exposed to temperatures of 100 °C. Ammonium nitrate (NH4NO3) decomposes exothermically releasing 378 kJ/g mol. Its rate of decomposition can be described by the Arrhenius equation ... 

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