Carbon combination with elements

But why do they bum wood, say, when cold The principal reactions occurring when natural materials bum involve chemical oxidation, with carbohydrates combining with elemental oxygen to yield water and carbon dioxide. Nitrogen... 

Acid rain is one of the worst manifestations of the damage we, as humans, inflict on our planet. Chemicals combine with elemental oxygen during the burning of fossil fuels, trees and rubbish to generate large amounts of acidic oxides such as nitrogen monoxide (NO), carbon dioxide (CO2) and sulphur dioxide (SO2). 

Many metals are relatively inert they don t combine chemically with other substances as easily as non-metals do. For example, iron rusts and copper oxidizes. The green color of copper domes comes from a thin layer of a copper carbonate. But neither iron nor copper spontaneously combines with elements other than oxygen that are found in the natural environment. Otherwise, we would not have copper coins,... 

A method was devised for estimating aromatic plus olefinic carbon content and total ring content. H NMR spectral data are used to estimate aromatic plus olefinic carbon content, and 13C NMR and NMR spectral data are combined with elemental carbon, hydrogen, and ash analyses to determine ring content. 

Only compounds in which carbon is combined with elements of similar or lower electronegativity are called carbides (see also Section 7-9). 

When two nonmetalhc elements combine, the product formed often depends on the relative quantities of the reactants present. For example, when carbon combines with oxygen, either of two possible compounds may be produced carbon monoxide or carbon dioxide. When the supply of oxygen is limited, carbon monoxide is produced, but when excess oxygen is available, carbon dioxide results ... 

Accordingly, carbon takes its place with the three groups of elements mentioned earlier as the only representative yet known of a fourth group (the compounds of boron and silicon being still too little known). Its simplest combinations with elements of the three other groups are ... 

Although it constimtes only about 0.09 percent by mass of Earth s crust, carbon is an essential element of living matter. It is found free in the form of diamond and graphite (see Figure 8.17), and it is also a component of natural gas, petroleum, and coal. (Coal is a natural dark-brown to black solid used as a fuel it is formed from fossilized plants and consists of amorphous carbon with various organic and some inorganic compounds.) Carbon combines with oxygen to form carbon dioxide in the atmosphere and occurs as carbonate in limestone and chalk. 

Organic compounds. Compounds that contain carbon, usually in combination with elements such as hydrogen, oxygen, nitrogen, and sulfur. (2.7)... 

ORGANIC Relating to or obtained from living things. In chemistry, refers to compounds made of carbon combined with other elements. 

Carbonic oxide is a compound radical that is, it acts like an element, combining with elements. Thus, it combines with chlorinej with oxygen, with metals. In this point of view it is a most interesting compound but, like cyanogen, comes to be treated of as a compound radicrd in the organic division of this work. 

The combination of oxygen with other elements is an example of a process chemists call oxidation. In the case of combustion reactions, we say that the fuel is being oxidized and that the oxidation process is something beneficial. In the case of corrosion reactions, metals are being oxidized, as in the case where iron (or steel) combines with oxygen to form rust (ferric oxide, Fe Oj), which is an undesirable process. Most metals are obtained from deposits of their ores where the metal—for example, copper, iron, zinc, aluminum, or lead—occurs in combination with elements such as oxygen, sulfur, or a halogen, or with a combinations of elements as in a silicate, an arsenate, or a carbonate. 

NMR measurements have been combined with elemental and mass balance data to determine the extent of aromatization during pyrolysis. Hershkowitz et al7 were the first to quantify the increase in the aromatic carbon formed during pyrolysis of Colorado oil shale. Their experiments were conducted at a slow heating rate, under high pressure (2600 kPa) N2 or H2 atmospheres, at temperatures up to 600°C, followed by a 10 min soak period at this temperature. In an N2 atmosphere, the total aromatic carbon in the products increased by 83% over that in the raw shale. In H2 the increase was only 17%. In addition, 87% of the raw shale carbon was recovered in the oil when heated under H2, compared with 67% under N2. An increase in aromatic carbon of about 83% has been observed in pyrolysis studies of Green River oil shale at heating rates of l-720 Ch to 500°C. ... 

Aluminum is an effective sintering aid for B4C and SiC ceramics if combined with elemental boron and carbon. Phase relations in the B-C-Al-Si system may hence indicate suitable procedures to initiate transient liquid phase or enhanced solid-state sintering. Furthermore, liquid A1 may be used to infiltrate porous B4C bodies acting as a reinforcing phase. 

Formulas that show the connections in this way are known as structural formulas, whereas formulas that give just one symbol for each element present are called molecular formulas. The molecular formula for methane is GH, for example. Methane and the many millions of compounds that contain carbon combined with hydrogen— and often also with nitrogen, oxygen, phosphorus, or sulfur—are known as organic compounds. 

Dalton s third hypothesis supports another important law, the law of multiple proportions. According to the law, if two elements can combine to form more than one compound, the masses of one element that combine with a fixed mass of the other element are in ratios of small whole numbers. Dalton s theory explains the law of multiple proportions quite simply Different compounds made up of the same elements differ in the number of atoms of each kind that combine. For example, carbon forms two stable compounds with oxygen, namely, carbon monoxide and carbon dioxide. Modem measurement techniques indicate that one atom of carbon combines with one atom of oxygen in carbon monoxide and with two atoms of oxygen in carbon dioxide. Thus, the ratio of oxygen in carbon monoxide to oxygen in carbon dioxide is 1 2. This result is consistent with the law of multiple proportions (Figure 2.2). 

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