Flammable mixtures Aqueous solutions

Mixtures of perchlorate salts with finely divided or fibrous organic materials are likely to be explosive. Porous or fibrous materials exposed to aqueous solutions and then dried are rendered explosively flammable and are easily ignited. 

There is an account of an incident involving combustion/explosion in the free space of a weak ammonia liquor tank where detailed examination revealed no evidence for an ignition source [5]. The existence of ammonia—air mixtures able to bum only in sufficiently large enclosed volumes was established [6], Previous data on flammability has been summarised and extended by determination of flammability characteristics of ammonia admixed with dry air and oxygen-deficient air at temperatures from ambient up to 400°C. Similar work with added water vapour at 80°C shows that aqueous solutions of below 5% ammonia content do not produce flammable vapours at any temperature, and that above 49°C no flammable vapours are produced by ammonia solution of any concentration. Some data on ignition energy and explosibility are also given [7], Two US incidents serve as a reminder of the considerable explosive potential of ammonia—air mixtures in confined volumes. An... 

To a suspension of LAH (6.50 g, 171 mmol) in THF (90 mL) at 0 °C was added dropwise a solution of the diacid (3.40 g, 17.0 mmol) in THF (30 mL). The mixture was heated at reflux for 1 h and then cooled to 0 °C. The mixture was then treated dropwise with water (13 mL) and 10% aqueous sodium hydroxide (10 mL). Note extreme care should be practiced during the quenching process. As this process is exothermic and produces flammable hydrogen gas, it is highly advisable to cool the reaction mixture to 0 °C prior to quenching and to add the water and aqueous solution of sodium hydroxide cautiously. The mixture was hltered over Na2SO4, and the hltrate was evaporated under reduced pressure to give 2.65 (91%) of the diol. 

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