Naphthalene nitration test

C) Nitration Test. Place in a 30 or 50 ml Erlenmeyer flask 6 ml of a mixture of equal volumes of concentrated nitric acid and concentrated sulfuric acid. Add 2 ml of benzene and shake for a minute. In another flask treat in the same manner 2 g of naphthalene. Place flasks in a water bath and warm at 50° for 10 minutes. Shake the mixture frequently, using care that no acid is splattered. TFeor your goggles. After the mixtures are heated pour each into 50 ml of water and note whether any yellow oil or solid separates out. The nitro compound is separated and handed to the instructor. Compare the nitronaphthalene with the original compound. Record in your note book the observations and explanation. 

The nitration of naphthalene was used as a test reaction [37]. As a consequence of having two aromatic rings, a particularly large variety of nitration products are in principle possible. This refers to multiplicity of nitration and to positional selectivity for each nitration step. 

A further test of this interpretation is provided by the activation energies of the reactions that occur at the limiting rate. The observed activation energies for the nitration of mesitylene and naphthalene in 67.1% sulphuric acid are 75.3 and 64.8 kJ mol"1 respectively (Coombes et al., 1968). On the interpretation in terms of reaction on encounter the activation energy should be the sum of the AH° term for the formation of the nitronium ion (43 kJ mol"1 in 68.3% sulphuric acid) (Hartshorn et al., 1972), and the term derived from the temperature dependence of the viscosity of the solvent (24 kJ mol"1 see (8) and Table 2). Thus, the expected activation energy is ca. 67 kJ mol-1, a value in reasonable agreement with the experimental results. 

The nitronaphthalene precipitated by cooling, after washing with water should not melt below 51 °C and should not smell of naphthalene. If the test is satisfactory, a part of the mixture in the nitrator is conveyed to a separator and the remaining 2500 1. is left for the next batch. The latter quantity is controlled by the depth of... 

Dinitroglycerin Collodion cotton Nitrotoluenes Naphthalene Ammonium nitrate Potassium nitrate Sodium nitrate Alkali chloride Trauzl Test, cc Charge limit in firedamp, grams 27.4 0.6 4.5 0.5 32.0 2.0 5.5 27.5 233 350 27.4 0.6 3.5 32.0 2.0 4.5 30.0 205 700... 

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