Meta-arsenites

Alternatively, prepare the sodium meta-arsenite solution by dissolving 39 6 g. A.R. arsenious oxide and 32 g. of A.R. sodium hydroxide in 600 ml. of water. 

Arsenites of the alkali metals are very soluble in water, those of the alkaline earth metals less so, and those of the heavy metals are virtually insoluble. Many of the salts are obtained as meta-arsenites, e.g. NaAs02, which comprises polymeric chain anions formed by comer linkage of pyramidal ASO3 groups and held together by Na ions ... 

Sodium arsenite (01m). Dissolve 13 0 g sodium meta-arsenite, NaAs02, in water and dilute to 1 litre. 

Lithium meta-arsenite, LiAs02.—At 25c C. the ternary system lithium oxide—arscnious oxide— voter indicates the existence of a meta-arsenite soluble in water without decomposition.1... 

Sodium arsenites.—No crystalline arsenite has been obtained, but solutions of the meta-arsenite, NaAsOa, the diarsenite NaHAs204, and trisodium ortkoarsenite, Na3As03, have been prepared.4... 

Ammonium arsenites.—Between 70° and 80° C. ammonia reacts with a solution of arsenious oxide to form acicular crystals of ammonium meta-arsenite, NH AsOg.12 With concentrated ammonia arsenious oxide yields the crystalline ammonium pyroarsenite, (NH4)4As205, an unstable substance decomposed with evolution of ammonia on exposure to air.13... 

Sodium Arsenite. Sodium meta -arsenite. Approx NaAs02. The product of commerce is 95-98% pure. 

Waterborne Salts. Waterborne salts for wood preservation include zinc chloride, chro-mated zinc chloride, copperized chromated zinc chloride, zinc meta arsenite, chromated zinc arsenate, chromated copper arsenate, ammoniacal copper arsenite, acid copper chromate, and fluor chrome arsenate phenol. These chemicals leave little odor and have little effect on the appearance of the wood, which may also be painted. The zinc chloride salts, at high penetrations, also provide fire retardance.Wood should be reseasoned before use because this type of chemical treatment injects a large amount of water into the wood. 

Dissolve 20 g of analytical reagent sodium meta-arsenite Na2As02 in 1000 ml of de-ionized water. Store in a well-stoppered polyethylene bottle. The solution is stable indefinitely. 

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