Sodium chlorate, formation

Sodium chlorate, formation of, in preparation of chlorine (I) oxide in carbon tetrachloride solution, 5 159n. 

In Eq. (18.1), sodium hypochlorite is produced by feeding chlorine into a 30% aqueous caustic solution in a circulating reactor/cooler system. To avoid sodium chlorate formation, the reaction temperature is kept below 30°C and NaOH concentration is kept below 1 g/liter. Typical reaction temperature is 5 °C132. 

Sodium Chlorite. The standard enthalpy, Gibbs free energy of formation, and standard entropy for aqueous chlorite ions ate AH° = —66.5 kJ/mol ( — 15.9 kcal/mol), AG = 17.2 kJ/mol (4.1 kcal/mol), and S° = 0.1883 kJ/(molK) (0.045 kcal/(molK)), respectively (107). The thermal decomposition products of NaClO, in the 175—200°C temperature range ate sodium chlorate and sodium chloride (102,109) ... 

A saucepan of vegetable stew had been heated too long and had formed a thick carbonised adherent cake. In an attempt to clean the pan, 1 1 of domestic bleach was added and the pan was left to heat on an electric hotplate. Again it was left too long and after all the water had evaporated, the residue exploded violently. This was attributed to formation of sodium chlorate dining evaporation, and ignition of the overheated chlorate-impregnated carbonised mass. 

MCA Case History No. 282 Erroneous addition of cone, sulfuric acid to sodium chlorate instead of sodium chloride caused an explosion owing to formation of chlorine dioxide [1]. Accidental contact of 93% acid on clothing previously splashed with sodium chlorate caused immediate ignition [2],... 

This is the reaction by which sodium chlorate is manufactured commercially. In the present context, however, the formation of chlorates is generally undesirable since they tend to be explosive and toxic. The reaction given by Equation 26.2 is strongly affected by pH and temperature as well as the hypochlorite ion concentration. As the alkali becomes exhausted, and the system is thus over-chlorinated, the rate of chlorate formation is greatly accelerated as the reaction becomes auto-catalysed by hypo-chlorous acid. The acid is formed by... 

The converse obviously applies to ammonium nitrate explosives, which must not contain any chlorates, since during storage a double exchange reaction may occur resulting in the formation of ammonium chlorate (p. 476, Vol. II), an unstable substance which decomposes spontaneously. A number of patents were taken out between 1880 and 1895, for explosives based on the use of ammonium chlorate or mixtures of ammonium nitrate with potassium or sodium chlorate. Many accidents which occurred through the spontaneous decomposition of these explosives proved the impossibility of using mixtures containing both chlorates and ammonium salts (Hantke [79]). 

Cupric acetate, polluted atmosphere, sodium chlorate, sodium formate, sodium hydroxide, sodium nitrate, sodium nitrite, sodium sulfate sulphide and sodium tungstate SCC of alloys C26000 C44300 > C70600 Brass Admiralty brass... 

---