Soda, Ammonia Caustic

Sodium hydroxide (caustic soda) Ammonia—caustic dust and mist... 

When added to a dilute solution of caustic soda or caustic potash, it forms [Sb(OH)6] ion in the solution, from which the sodium or potassium salt, NaSb(OH)e or KSb(OH)6 crystaUizes out. It forms two adducts with ammonia, a red triammine, SbCls 3NHs, and a colorless tetraammine, SbCls 4NHs. SbCls dissociates on heating to trichloride and chlorine dissociation comenc-ing around 120°C and completing at 300°C. 

In caustic soda or caustic potash solution, mercury(TI) iodide forms complex salts, Na2Hgl4 and K2Hgl4, respectively. Alkaline solution of this complex in excess potassium hydroxide is known as Nessler s reagent, used to analyze ammonia. The reaction of Nessler s reagent with ammonia may be written as ... 

The tetrahydrate, Ni(CN)2 4H2O constitutes apple green plates or powder loses water of crystaUization on heating at 200°C decomposes on further heating insoluble in water shghtly soluble in dilute acids soluble in potassium cyanide solution and in ammonia, caustic soda, caustic potash and other bases. 

Strong alkaline solutions of caustic soda or caustic potash dissolve tin forming the stannate, Na2Sn03, or K2Sn03. The metal is stable in dilute solutions of ammonia or sodium carbonate. 

It is possible to oxidize all the CH2OH groups to carboxylic groups, if the conditions of reaction are sufficiently severe, when the content of COOH may reach 25%. The product obtained in this way is a polyanhydroglucuronic add, known as carboxycellulose or celluronic acid. When half the CH2OH groups present in the cellulose are oxidized, a product with a 13% COOH content is obtained, soluble in dilute solutions of caustic soda, ammonia and sodium carbonate. Celluronic acid can form esters with nitric acid. The properties of these esters will be discussed later. 

State the chemical name and formula of lime, lime water, limestone, chloride of lime, bleaching powder, marble, muriatic acid, oil of vitriol, blue vitriol, ammonia, sal ammoniac, salt, soda, potash, caustic soda, quicklime, slaked lime, cream of tartar. 

Fatty Alcohol Ether Sulfates. Probably the most important derivatives of fatty alcohol in the C12-C14 and C12-C16 ranges are the fatty alcohol ether sulfates. They are produced by the sulfation of the fatty alcohol, containing 2-3 moles of ethylene oxide, with sulfur trioxide or chlorosulfonic acid and subsequently neutralized with caustic soda, ammonia, or an alkanolamine. The ether sulfates possess superior properties over the fatty alcohol sulfates. They have unlimited water solubility, are unaffected by water hardness, and possess superior skin compatibility. Accordingly, they are used in liquid shampoos and bath preparations. One characteristic of this material is its ability to increase its viscosity by the addition of an electrolyte such as salt (5). 

A basic guideline in a choice of corrosion environments during the test of RubCon specimens was their wide spreading into industrial production. Such environments were water, 30% and 70% solutions of sulfuric acid, 5% solutions of phosphoric and acetic acids, 3% solution of nitric acid, 3% and 30% solutions of hydrochloric acid, 10% solutions of lactic and lemon acids, caustic soda and caustic potash, diesel fuel, acetone, 25% water solution of ammonia, 30% solution of copper vitriol, and a saturated solution of sodium chloride. Chemical resistance of RubCon was estimated on test specimens measuring 4 x 4 x 16 cm [21-23],... 

Vapor forms an explosive mixture with air in the range 2.8-31.0% by volume of air. It undergoes self-polymerization, liberating heat. It polymerizes at elevated temperatures. Closed containers may rupture violently as a result of polymerization. The reaction may become extremely violent in contact with alkaline substances such as caustic soda, amines, or ammonia. Contact with acid can result in polymerization, liberating heat. However, the reaction is not as violent as that with caustic soda or caustic potash. 

The chemical resistance of PC is poor and hydrolysis of aliphatic PC s is more prominent than that of bis-phenol A PC s. There is resistance to dilute (25%) mineral acids and dilute alkaline solutions other than caustic soda and caustic potash. Where the resin comes into contact with organophilic hydrolysing agents such as ammonia and the amines, the benzene rings give little protection and reaction is quite rapid. The absence of both secondary and tertiary C-H bonds leads to a high measure of oxidative stability. Oxidation takes place only when thin films are heated in air to temperatures above 300°C. 

Sulfur Acid Chlorine Caustic Soda Ammonia... 

Standard loop neutralisers use caustic soda solution as neutralising agent. Other agents such as aqueous or s ydrous ammonia, caustic potash, or ethanolamine can also be used. In addition liquid additives such as ethyl alcohol and urea solutions will blend with the paste in the loop reactors. 

Caustic Soda. Diaphragm cell caustic is commercially purified by the DH process or the ammonia extraction method offered by PPG and OxyTech (see Fig. 38), essentially involving Hquid—Hquid extraction to reduce the salt and sodium chlorate content (86). Thus 50% caustic comes in contact with ammonia in a countercurrent fashion at 60°C and up to 2500 kPa (25 atm) pressure, the Hquid NH absorbing salt, chlorate, carbonate, water, and some caustic. The overflow from the reactor is stripped of NH, which is then concentrated and returned to the extraction process. The product, about 62% NaOH and devoid of impurities, is stripped free of NH, which is concentrated and recirculated. MetaUic impurities can be reduced to low concentrations by electrolysis employing porous cathodes. The caustic is then freed of Fe, Ni, Pb, and Cu ions, which are deposited on the cathode. 

Manufacture, Shipment, and Analysis. In the United States, sodium and potassium thiocyanates are made by adding caustic soda or potash to ammonium thiocyanate, followed by evaporation of the ammonia and water. The products are sold either as 50—55 wt % aqueous solutions, in the case of sodium thiocyanate, or as the crystalline soHds with one grade containing 5 wt % water and a higher assay grade containing a maximum of 2 wt % water. In Europe, the thiocyanates may be made by direct sulfurization of the corresponding cyanide. The acute LD q (rat, oral) of sodium thiocyanate is 764 mg/kg, accompanied by convulsions and respiratory failure LD q (mouse, oral) is 362 mg/kg. The lowest pubhshed toxic dose for potassium thiocyanate is 80—428 mg/kg, with hallucinations, convulsions, or muscular weakness. The acute LD q (rat, oral) for potassium thiocyanate is 854 mg/kg, with convulsions and respiratory failure. 

Because dimethyl sulfate looks like water, operations are preferably not performed when water is present, eg, wet floors or rain. Any spills or leaks should not be left unattended they should be contained, and mnoff to sewers should be avoided. Minor spills should be flooded with water to dilute and hydroly2e the dimethyl sulfate. The area should then be covered with a dilute (2—5 wt %) caustic solution or a dilute (2—5 wt %) ammonia solution, or soda ash may be sprinkled over the neat liquid and the mix wetted with a gende spray of water. The neutrafi2ing agent should remain on the affected area for 24 h and then should be washed away. Only personnel wearing protective equipment should perform these operations. The product bulletins should be consulted for procedures to be followed for more severe spills. Concentrated ammonia should not be used with neat dimethyl sulfate because explosions have resulted after their contact (128). 

There are two serious problems associated with continuous tar distillation. Coal tar contains two types of components highly corrosive to ferrous metals. The ammonium salts, mainly ammonium chloride, associated with the entrained Hquor remain in the tar after dehydration, tend to dissociate with the production of hydrochloric acid and cause rapid deterioration of any part of the plant in which these vapors and steam are present above 240°C. Condensers on the dehydration column and fractionation columns are also attacked. This form of corrosion is controlled by the addition of alkaU (10% sodium carbonate solution or 40% caustic soda) to the cmde tar in an amount equivalent to the fixed ammonia content. 

No reaction takes place below 500°C when sodium cyanide and sodium hydroxide are heated in the absence of water and oxygen. Above 500°C, sodium carbonate, sodium cyanamide [19981-17-0] sodium oxide, and hydrogen are produced. In the presence of small amounts of water at 500°C decomposition occurs with the formation of ammonia and sodium formate, and the latter is converted into sodium carbonate and hydrogen by the caustic soda. In the presence of excess oxygen, sodium carbonate, nitrogen, and water are produced (53). 

Inorga.nicNIa.teria.ls. These include acids (sulfuric, nitric, hydrochloric, and phosphoric), bases (caustic soda, caustic potash, soda ash, sodium carbonate, ammonia, and lime), salts (sodium chloride, sodium nitrite, and sodium sulfide) and other substances such as chlorine, bromine, phosphoms chlorides, and sulfur chlorides. The important point is that there is a significant usage of at least one inorganic material in all processes, and the overall toimage used by, and therefore the cost to, the dye industry is high. 

Copper alloys are attacked at high pH. However, attack is usually caused not by elevated pH alone but because of copper complexation by ammonia or substituted ammonium compounds. In fact, copper resists corrosion in caustic solutions. For example, corrosion rates in hot caustic soda may be less than 1 mil/y (0.025 mm/y). 

In some materials and environments, cracks grow steadily under a constant stress intensity K which is much less than (Fig. 23.8). This is obviously dangerous a structure which is safe when built can become unsafe with time. Examples are brass in ammonia, mild steel in caustic soda, and some A1 and Ti alloys in salt water. 

Two classes of resol are generally distinguished, water-soluble resins prepared using caustic soda as catalyst, and spirit-soluble resins which are catalysed by addition of ammonia. The water-soluble resins are usually only partially dehydrated during manufacture to give an aqueous resin solution with a solids content of about 70%. The solution viscosity can critically affect the success in a given application. Water-soluble resols are used mainly for mechanical grade paper and cloth laminates and in decorative laminates. 

Alkali Ammonia Biocides Sodium hydroxide (caustic soda) Potassium hydroxide (caustic potash) Calcium oxide (lime) Calcium hydroxide Sodium, potassium and calcium carbonates Ammonia (q.v.)... 

Reduce fixed ammonia content in ammonia liquor by using caustic soda and steam stripping. 

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