Ammonia sulphite

CCls CHO. A colourless oily liquid with a pungent odour b.p. 98°C. Manut actured by the action of chlorine on ethanol it is also made by the chlorination of ethanal. When allowed to stand, it changes slowly to a white solid. Addition compounds are formed with water see chloral hydrate), ammonia, sodium hydrogen sulphite, alcohols, and some amines and amides. Oxidized by nitric acid to tri-chloroethanoic acid. Decomposed by alkalis to chloroform and a methanoate a convenient method of obtaining pure CHCI3. It is used for the manufacture of DDT. It is also used as a hypnotic. 

Procedure. Dissolve 0.0079 g of pure lead nitrate in 1 L of water in a graduated flask. To 10.0 mL of this solution (containing about 50 p.g of lead) contained in a 250 mL separatory funnel, add 75 mL of ammonia-cyanide-sulphite mixture (Note 1), adjust the pH of the solution to 9.5 (pH meter) by the cautious addition of hydrochloric acid (CARE ), then add 7.5 mL of a 0.005 per cent solution of dithizone in chloroform (Note 2), followed by 17.5 mL of chloroform. Shake for 1 minute, and allow the phases to separate. Determine the absorbance at 510 nm against a blank solution in a 1.0 cm absorption cell. A further extraction of the same solution gives zero absorption indicative of the complete extraction of the lead. Almost the same absorbance is obtained in the presence of 100 pg of copper ion and 100 pg of zinc ion. 

Notes. (1) This solution is prepared by diluting 35 mL of concentrated ammonia solution (sp. gr. 0.88) and 3.0 mL of 10 per cent potassium cyanide solution (caution) to 100 mL, and then dissolving 0.15 g of sodium sulphite in the solution. 

Determination of sulphite by oxidation to sulphate and precipitation as barium sulphate Discussion. Sulphites may be readily converted into sulphates by boiling with excess of bromine water, sodium hypochlorite, sodium hypobromite, or ammoniacal hydrogen peroxide (equal volumes of 20-volume hydrogen peroxide and 1 1 ammonia solution). The excess of the reagent is decomposed by boiling, the solution acidified with hydrochloric acid, precipitated with barium chloride solution, and the barium sulphate collected and weighed in the usual manner (Section 11.72). 

The alkaline sodium sulphite solution may be replaced by saturated amtnonlum sulphite solution prepared as follows. Pass sulphur dioxide into a mixture of 1 part of concentrated ammonia solution (sp. gr. 0-88) and two parts of crushed ice in a freezing mixture imtil the liquid smells strongly of sulphur dioxide, and then neutralise with ammonia solution. This solution slowly deposits ammonium sulphite crystals and contains about 0-25 g. of SOj per ml. Use 60 ml. of this ice-cold ammonium sulphite solution to which 8 ml. of concentrated ammonia solution are added. After the addition of the solution of p-nitrophenyldiazonium chloride, allow the mixture to stand for 1 hour in a freezing mixture, filter oft the yellow precipitate of ammonium p-nitrophenyUiydrazine disulphonate, heat it on a water bath with 20 ml. of concentrated hydrochloric acid at 70-80° for 7 minutes, cool the blood-red solution, and dissolve the resulting precipitate of p-nitrophenylhydr-azine hydrochloride and ammonium salts in water, and isolate the base as above. 

Any substance used to prevent premature coagulation of rubber latex the commonest are ammonia, sodium sulphite and formaldehyde. Antidegradant... 

The napkthols are in many respects still more reactive than phenol. This is shown most distinctly by the fact that the naphthyl ethers can be obtained by the method used for the preparation of esters of carboxylic acids, namely, directly by the action of hydrogen chloride on the phenol in the presence of the alcohol. The naphthols, moreover, react readily with zinc-ammonium chloride and with ammonium sulphite and ammonia to yield naphthylamines. The second of these two methods is a general one. It was investigated by H. Bucherer. 

In the other study [155], ammonia-complexed Hg(N03)2 was mixed with the selenosulphate solution. As for the corresponding HgS deposition, a white precipitate formed on addition of ammonia to the HgCNOs) [Eq. (4.9)]. This precipitate dissolved partly in the excess ammonia used, due to formation of various am-mine complexes, and completely when the selenosulphate solution was added, due to additional formation of selenosulphate (and maybe sulphite from the excess sulphite in the selenosulphite solution) complexes. It is likely that mixed ammine-selenosulphate/sulphite complexes were formed. The deposition was carried out on polyester substrates (the transparencies used in overhead projectors) at 10°C. Deposition occurred over several hours to a terminal thickness of ca. 250 nm. Bulk precipitation occurred in parallel with the deposition, suggesting that the cluster mechanism was dominant. 

Zinc sulphite also unites with ammonia, forming monammino-zinc sulphite, [Zn(NH3)]S03 diammino-zinc sulphite, [Zn(NH3)2]S03 and triammino-zinc sulphite, [Zn(NH3)3]S03.2... 

Dissolved in dilute aqueous acid, then ppted by addn of dilute aqueous ammonia or alkali carbonates. (Epinephrine readily oxidises in neutral alkaline soln. This can be diminished if a little sulphite is added). 

The sulphites of potassa and ammonia may be prepared in a similar manner to that of soda, by passing sulphurous acid through a solution of the alkalies or their carbonates. 

With the alkalis the corresponding sulphite, thiosulphate and ammonia are formed ... 

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