Carbon free

Lassaigne s test is obviously a test also for carbon in the presence of nitrogen. It can be used therefore to detect nitrogen in carbon-free inorganic compounds, e.g., complex nitrites, amino-sulphonic acid derivatives, etc., but such compounds must before fusion with sodium be mixed with some non-volatile nitrogen-free organic compound such as starch... 

Solid NaOH is always contaminated with carbonate due to its contact with the atmosphere and cannot be used to prepare carbonate-free solutions of NaOH. Solutions of carbonate-free NaOH can be prepared from 50% w/v NaOH since Na2C03 is very insoluble in concentrated NaOH. When CO2 is absorbed, Na2C03... 

Fig. 6. Speciation diagram of plutonium as function of Eb and pH in aqueous solution at 25°C (a) carbonate-free (89) (b) 0.004 M total carbonate (90). Eb...

An important item in this array of matenals is the class known as maraging steels. This group of high nickel martensitic steels contain so Htde carbon that they are often referred to as carbon-free iron—nickel martensites (54). Carbon-free iron—nickel martensite with certain alloying elements is relatively soft and ductile and becomes hard, strong, and tough when subjected to an aging treatment at around 480°C. 

Industrial by-products are becoming more widely used as raw materials for cement, eg, slags contain carbonate-free lime, as well as substantial levels of silica and alumina. Fly ash from utility boilers can often be a suitable feed component, because it is already finely dispersed and provides silica and alumina. Even vegetable wastes, such as rice hull ash, provide a source of silica. Probably 50% of all industrial by-products are potential raw materials for Pordand cement manufacture. 

Tetramethylammonium hydroxide (5H2O) [10424-65-4 (5H2O), 75-59-2 (aq soln) ] M 181.2, m 63°, 65-68°. Freed from chloride ions by passage through an ion-exchange column (Amberlite IRA-400, prepared in its OH" form by passing 2M NaOH until the effluent was free from chloride ions, then washed with distilled H2O until neutral). A modification, to obtain carbonate-free hydroxide, uses the method of Davies and Nancollas [Nature 165 237 1950]. 

Kohle,/. coal charcoal carbon, kohlebeheizt, a. heated with coal, coal-fired. Kohle-chemie, /. coal(tar) chemistry, -druck, m. Photog.) carbon print, -fadenlampe, /. carbon-filament lamp, -feuerung, /. heating with coal coal furnace, kohlefrei, a. carbon-free. 

One part by weight of propyl-methyl-carbinyl allyl barbituric acid is added to enough alcohol to facilitate handling, in this case conveniently about six times its weight. To this is added a solution of sodium hydroxide, preferably carbonate-free or substantially so, containing °%38 parts by weight of sodium hydroxide, which is the amount of sodium hydroxide necessary to combine in equal molecular proportions with the propyl-methyl-carbinyl allyl barbituric acid. This solution is filtered clear, and is then evaporated under vacuum until the sodium propyl-methyl-carbinyl allyl barbiturate (alternatively named sodium allyl 1-methyl-butyl barbiturate) separates out in solid form. The salt as thus obtained in solid form contains a varying amount of moisture. 

Discussion. The hydroxides of sodium, potassium, and barium are generally employed for the preparation of solutions of standard alkalis they are water-soluble strong bases. Solutions made from aqueous ammonia are undesirable, because they tend to lose ammonia, especially if the concentration exceeds 0.5M moreover, it is a weak base, and difficulties arise in titrations with weak acids (compare Section 10.15). Sodium hydroxide is most commonly used because of its cheapness. None of these solid hydroxides can be obtained pure, so that a standard solution cannot be prepared by dissolving a known weight in a definite volume of water. Both sodium hydroxide and potassium hydroxide are extremely hygroscopic a certain amount of alkali carbonate and water are always present. Exact results cannot be obtained in the presence of carbonate with some indicators, and it is therefore necessary to discuss methods for the preparation of carbonate-free alkali solutions. For many purposes sodium hydroxide (which contains 1-2 per cent of sodium carbonate) is sufficiently pure. 

Carbonate-free sodium hydroxide solution. One of several methods of preparation may be used ... 

Procedure B (carbonate-free sodium hydroxide). Dissolve 50 g of sodium hydroxide in 50 mL of distilled water in a Pyrex flask, transfer to a 75 mL test-tube of Pyrex glass, and insert a well-fitting stopper covered with tin foil. Allow it to stand in a vertical position until the supernatant liquid is clear. For a 0.1 M sodium hydroxide solution carefully withdraw, using a pipette fitted with a filling device, 6.5 mL of the concentrated clear solution into a 1 L bottle or flask, and dilute quickly with 1 L of recently boiled-out water. 

This solution is widely employed, particularly for the titration of organic adds. Barium carbonate is insoluble, so that a clear solution is a carbonate-free strong alkali. The relative molecular mass of Ba(0H)2,8H20 is 315.50, but a standard solution cannot be prepared by direct weighing owing to the uncertainty of the... 

The processes that govern the formation of ash particles are complex and only partially understood (Figure 7.12). The mineral matter in pulverized coal is distributed in various forms some is essentially carbon-free and is designated as extraneous some occurs as mineral inclusions, typically 2-5 pm in size, dispersed in the coal matrix and some is atomically dispersed in the coal either as cations on carboxylic acid side chains or in porphyrin-type stmctures. The behavior of the mineral matter during combustion depends strongly on the chemical and physical state of the mineral inclusions. 

The carbon atom with the unpaired eiectron is another free radical, so the stage is set for propagation. The unpaired eiectron on the carbon atom attacks the n bond of another molecule of ethylene, making a new C—C a bond and ieaving yet another carbon free radical ... 

The process is conducted at 700 °C. It yields semicoke, which is popular as a smokeless domestic fuel. It can at times be used in boiler also to avoid smoke. Yield of coke oven gas is less, of tar high, and of ammonia less. Calorific value of coke oven gas generated is more. The process produces aliphatic natured tar. Following carbonization the coke discharging process is difficult as it swells extensively but does not shrink much upon carbonization. Free carbon in tar (produced from the cracking of hydrocarbons) is less Coke produced is weaker. Volatile matter in the coke produced is more. Hydrogen content in the coke oven gas is less. 

Ferrovanadium stands as a major industrially used form of vanadium. Similarly, it is in the form of ferroniobium that the bulk of niobium is used industrially. Aluminothermic reduction is an elegant metallurgical process for the production of these ferroalloys in their practically carbon-free forms. 

Indeed a natural alliance of carbon free technologies - nuclear and renewables - needs to be more active in aligning energy and environment policies, such as advocating all-source regimes. 

By 2050 total energy demand may have increased by a factor of 2 or 3 from today s. So, in order to meet such a condition, carbon-fiee energy supply would have to have grown by a factor of nearly 15. In that time-span the only sources of carbon free energy are renewables, such as solar biomass and wind, sequestration (exclusion of C02 from the atmosphere) and nuclear fission. There is considerable debate, but no conclusion, how fat and how fast renewables might grow, but clearly, if economic and acceptable, here is a major potential opening for nuclear power. 

P. Tulloch, L.L. Hoffman, Canadian beeswax analytical values and composition of hydro carbons, free acids and long chain esters, Journal of the American Oil Chemists Society, 49, 696 699 (1972). 

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