Online Encyclopedia
Search over 40,000 articles from the original, classic Encyclopedia Britannica, 11th Edition.
CH3CO2H
Online EncyclopediaEncyclopedia Home :: CAU-CHA
del.icio.us it!
|
CH3CO2H =118 C1CH2•CO2H =185° C12CH•CO2H =195°
C13C•CO2H =195°—200° 3°
According to See also:van 't Hoff the substitution of See also:chlorine atoms into a methyl See also:group occasions the following increments:
Cl in See also:CH3 66°
CI ,, CH2C1 39°
Cl „ CHC12 13°.
The introduction of chlorine, however, may involve a fall in the boiling-point, as is recorded by See also: E. Earp (Phil. Mag., 1893 151, 35, p. 458) has shown that, while an increase in molecular See also:weight is generally associated with a rise in the boiling-point, yet the symmetry of the resulting molecule may exert such a lowering effect that the final result is a diminution in the boiling-point. The See also:series H2S = -61°, CH3SH =21 °, (CH3)2S =41 ° is an example; in the first case, the molecular weight is in-creased and the symmetry diminished, the increase of boiling-point being 82°; in the second case the molecular weight is again increased but the molecule assumes a more symmetrical configuration, hence the comparatively slight increase of 20°. A similar depression is presented by methyl See also:alcohol (67°) and methyl See also:ether (—23°). Among the aromatic di-substitution derivatives the ortho compounds have the highest boiling-point, and the See also:meta boil at a higher, or about the same temperature as the See also:Para compounds. Of the tri-derivatives the symmetrical compounds boil at the lowest temperature, the See also:asymmetric next, and the vicinal at the highest. An ethylenic or See also:double See also:carbon See also:union in the aliphatic See also:hydrocarbons has, apparently, the same effect on the boiling-point as two See also:hydrogen atoms, since the compounds CJI2,,+2 and Cal-12a boil at about the same temperature. An acetylenic or triple linkage is associated with a rise in the boiling-point; for example, propargyl compounds boil about 19.5° higher than the corresponding propyl compound. Certain regularities attend the corresponding See also:property of the melting-point. A See also:rule applicable to organic compounds, due to Adolf v. See also:Baeyer and supported by F. S. Kipping (Jour. Chem. See also:Soc., 1893, 63, p. 465) states, that the melting-point of any See also:odd member of a homologous series is lower than the melting-point of the even member containing one carbon See also:atom less. This is true of the fatty See also:acid series, and the corresponding See also:ketones and alcohols, and also of the succinic acid series. Other regularities exist, but generally with many exceptions. It is to be noted that although the correlation of melting-point with constitution has not been See also:developed to such an extent as the chemical significance of other See also:physical properties, the melting-point is the most valuable test of the purity of a sub-stance, a circumstance due in considerable measure to the fact that impurities always tend to lower the melting-point. See also:Heat of See also:Combustion and Constitution.—In the See also:article See also:THERMOCHEMISTRY a See also:general See also:account of heats of formation of chemical compounds is given, and it is there shown that this See also:constant See also:measures the stability of the compound. In organic See also:chemistry it is more customary to See also:deal with the " heat of combustion,” i.e. the heat evolved when an organic compound is completely burned in See also:oxygen; the heat of formation is deduced from the fact that it is equal to the beats of formation of the products of combustion less the observed heat of combustion. The researches of See also:Julius See also:Thomsen and others have shown that in many cases definite conclusions regarding constitution can be See also:drawn from quantitative measurements of the heats of combustion; and in this article a See also:summary of the See also:chief results will be given, The identity of the four valencies of the carbon atom follows from the fact that the heats of combustion of methane, ethane, propane, trimethyl methane, and tetramethyl methane, have a constant difference in the See also:order given, viz. 158.6 calories; this means that the replacement of a hydrogen atom by a methyl group is attended by a constant increase in the heat of combustion. The same difference attends the introduction of the methyl group into many classes of compounds, for example, the paraffins, olefines, acetylenes, aromatic hydrocarbons, alcohols, See also:aldehydes, ketones and esters, while a slightly lower value (157.1) is found in the case of the halogen compounds, nitriles, See also:amines, acids, See also:ethers, sulphides and nitro compounds. It therefore appears that the difference between the heats of combustion of two adjacent members of a series of homologous compounds is practically a constant, and that this constant has two See also:average values, viz. 158.6 and 157.1. An important connexion between heats of combustion and constitution is found in the investigation of the effect of single, double and triple carbon linkages on the thermochemical constants. If twelve grammes of amorphous carbon be burnt to carbon dioxide under constant See also:volume, the heat evolved (96.96 cal.) does not measure the entire thermal effect, but the difference between this and the heat required to break down the carbon molecule into atoms. If the number of atoms in the carbon molecule be denoted by n, and the heat required to split off each atom from the molecule by d, then the See also:total heat required to break down a carbon molecule completely into atoms is nd. It follows that the true heat of combustion of carbon, i.e. the heat of combustion of one gramme-atom, is 96.96+4. The value of d can be evaluated by considering the combustion of amorphous carbon to carbon monoxide and carbon dioxide. In the first case the thermal effect of 58.58 calories actually observed must be increased by 2d to allow for the heat absorbed in splitting off two gramme-atoms of carbon; in the second case the thermal effect of 96.96 must be increased by d as above. Now in both cases one gramme-molecule of oxygen is decomposed, and the two oxygen atoms thus formed are combined with two carbon valencies. It follows that the thermal effects stated above must be equal, i.e.58.58+2d=96.96+d, and therefored=38.38. Theabsolute heat of combustion of a carbon atom is therefore 135.34 calories, and this is independent of the See also:form of the carbon burned. Consider now the combustion of a See also:hydrocarbon of the general See also:formula C„H2,.. We assume that each carbon atom and each hydrogen atom contributes equally to the thermal effect. If a be the heat evolved by each carbon atom, and t3 that by each hydrogen atom, the thermal effect may be expressed as H =na+2m/3-A, where A is the heat required to break the molecule into its constituent atoms. If the hydrocarbon be saturated, i.e. only contain single carbon linkages, then the number of such linkages is 2n-m, and if the thermal effect of such a linkage be X, thenthe termA.isobviously equal to (2n-m)X. The value of H then becomes H=na-+-2mi-(2n-m)X or nth-mn, where and rt are constants. Let double bonds be See also:present, in number p, and let the See also:energy due to such a See also:bond be Y. Then the number of single bonds is 2n-m-2p, and the heat of combustion becomes H1=nE+m+l+p(2X-Y). If triple bonds, q in number, occur also, and the energy of such a bond be Z, the See also:equation for H becomes H = nE+mn +P(2X-Y) +q(3X-Z). This is the general equation for calculating the heat of combustion of a hydrocarbon. It contains four independent constants; two of these may be calculated from the heats of combustion of saturated hydrocarbons, and the other two from the combustion of hydrocarbons containing double and triple linkages. By experiment it is found that the thermal effect of a double bond is much less than the effect of two single bonds, while a triple bond has a much smaller effect than three single bonds. J. Thomsen deduces the actual values of X, Y, Z to be 14.71, 13.27 and zero; the last value he considers to be in agreement with the labile See also:equilibrium of acetylenic compounds. One of the most important applications of these values is found in the case of the constitution of See also:benzene, where Thomsen decides in favour of the Claus formula, involving nine single carbon linkages, and rejects the See also:Kekule formula, which has three single and three double bonds (see See also:section IV.). The thermal effects of the See also:common organic substituents have also been investigated. The thermal effect of the " alcohol " group C.OH may be determined by finding the heat of formation of the alcohol and subtracting the thermal effects of the remaining linkages in the molecule. The average value for primary alcohols is 4467 cal., but many large See also:differences from this value obtain in certain cases. The thermal effects increase as one passes from primary to See also:tertiary alcohols, the values deduced from propyl and isopropyl alcohols and trimethyl carbinol being:—primary =45.08, secondary =50.39, tertiary =6o•98. The thermal effect of the aldehyde group has the average value 64.88 calories, i.e. considerably greater than the alcohol group. The ketone group corresponds to a thermal effect of 53.52 calories. It is remarkable that the difference in the heats of formation of ketones and the See also:paraffin containing one carbon atom less is 67.94 calories, which is the heat of formation of carbon monoxide at constant volume. It follows therefore that two hydrocarbon radicals are See also:bound to the carbon monoxide See also:residue with the same strength as they combine to form a paraffin. The average value for the carboxyl group is 119.75 calories, i.e. it is equal to the sum of the thermal effects of the aldehyde and carbonyl groups. The thermal effects of the See also:halogens are: chlorine =15.13 calories, bromine =7.68; iodine = -4.25 calories. It is remarkable that theposition of the halogen in the molecule has no effect on the heat of formation; for example, chlorpropylene and allylchloride, and also See also:ethylene dichloride and ethylidene dichloride, have equal heats of formation. The thermal effect of the ether group has an average value of 34'31 calories. This value does not hold in the case of r—~ methylene See also:oxide if we assign to it the formula H2C•O•CH2, but if the formula See also:H2C.O.CH2 (which assumes the presence of two See also:free valencies) be accepted, the calculated and observed heats of formation are in agreement. The See also:combination of See also:nitrogen with carbon may result in the formation of nitriles, cyanides, or primary, secondary or tertiary amines. Thomsen deduced that a single bond between a carbon and a nitrogen gramme-atom corresponds to a thermal effect of 2.77 calories, a double bond to 5'44, and a See also:treble bond to 8.31. From this he infers that See also:cyanogen is C : N- N :C and not N C •C ; N, that hydrocyanic acid is HC.N, and acetonitrile CH3.0 i N. In the case of the amines he decides in favour of the formulae H2C:NH3 See also:H3C~See also:NH2 H8C>NH•CH2 primary, secondary, tertiary. These involve pentavalent nitrogen. These formulae, however, only apply to aliphatic amines; the results obtained in the aromatic series are in accordance with the usual formulae. See also:Optical Relations. See also:Refraction and See also:Composition.—Reference should be made to the article REFRACTION for the general discussion of the phenomenon known as the refraction of See also:light. It is there shown that every substance, transparent to light, has a definite refractive See also:index, which is the ratio of the velocity of light in vacuo to its velocity in the See also:medium to which the refractive index refers. The refractive index of any substance varies with (I) the See also:wave-length of the light; (2) with temperature; and (3) with the See also:state of See also:aggregation. The first cause of variation may be at present ignored; its significance will become apparent when we consider See also:dispersion (vide infra). The second and third causes, however, are of greater importance, since they are associated with the molecular See also:condition of the substance; hence, it is obvious that it is only from some See also:function of the refractive index which is independent of temperature See also:variations and changes of state (i.e. it must remain constant for the same substance at any temperature and in any form) that quantitative relations between refractivity and chemical composition can be derived.
The See also:pioneer See also:work in this See also: P. See also:Dale; the more See also:simple formula (n-1)/d, which remained constant for gases and vapours, but exhibited slight discrepancies when liquids were examined over a wide range of temperature, being adopted. The subject was next taken up by Hans Landolt, who, from an immense number of observations, supported in a general way the formula of Gladstone and Dale. He introduced the See also:idea of comparing the refractivity of equimolecular quantities of different substances by multiplying the function (n—i)/d by the molecular weight (M) of the substance, and investigated the relations of chemical grouping to refractivity. Although establishing certain general relations between atomic and molecular refractions, the results were somewhat vitiated by the inadequacy of the empirical function which he employed, since it was by no means a constant which depended only on the actual composition of the substance and was independent of its physical condition. A more accurate expression (n2—1)/(n2+2)d was 70 suggested in 188o independently and almost simultaneously by L. V. Lorenz of See also:Copenhagen and H. A. Lorentz of See also:Leiden, from considerations based on the See also:Clausius-Mossotti theory of dielectrics. Assuming that the molecules are spherical, R. J. E. Clausius and O. F. Mossotti found a relation between the See also:dielectric constant and the space actually occupied by the molecules, viz. K = (r +2a)/(I -a), or a=(K-1)/(K+2.), where K is the dielectric constant and a the fraction of the total volume actually occupied by See also:matter. According to the electromagnetic theory of light K = N2, where N is the refractive index for rays of See also:infinite wave-length. Making this substitution, and dividing by d, the density of the substance, we obtain aid = (N2 - 1)/(N2 +2)d. Since aid is the real specific volume of the molecule, it is therefore a constant; hence (N2-1)/(N2+2)d is also a constant and is independent of all changes of temperature, pressure, and of the state of aggregation. To determine N recourse must be made to See also:Cauchy's formula of dispersion (q.v.), n=A+B/X2+C/X4+... from which, by extrapolation, X becoming infinite, we obtain N = A. In the case of substances possessing anomalous dispersion, the See also:direct measurement of the refractive index for Hertzian waves of very See also:long wave-length may be employed. It is found experimentally that the Lorenz and Lorentz function holds fairly well, and better than the Gladstone and Dale formula. This is shown by the following observations of Ri hlmann on See also:water, the light used being the D See also:line of the spectrum:- t. (n- Yd. (n2--I)/(n2+2)d. 0 0.3338 0.2061 10 0.3338 0.2061 20 0.3336 0.2061 90 0.3321 0.2059 100 0.3323 0.2061 Eykmann's observations also support the approximate constancy of the Lorenz-Lorentz formula over wide temperature differences, but in some cases the deviation exceeds the errors of observation. The values are for the Ha line: Substance. Temp. (n2-1)/(n2+2)d. Isosafrol., C,oHio02 141'10 1° ° 0.2962 9Diphenyl ethylene, See also:Collin # 122- 0'3339 See also:Quinoline, CBH7N . . . 16.2° 0.3187 1141° 0.3225 The empirical formula (n2-I)/(n2+o•4)d apparently gives more constant values with change of temperature than the Lorenz-Lorentz form. The superiority of the Lorenz-Lorentz formula over the Gladstone and Dale formula for changes of state is shown by the following observations of See also:Bruhl (Zeit. f. phys. Chem., 1891, 71, p. 4). The values are for the D line:- Landolt and Gladstone, and at a later date J. W. Briihl, have investigated the relations existing between the refractive power Additive and composition. To Landolt is due the proof that, relations. In general, isomers, i.e. compounds having the same composition, have equal molecular refractions, and that equal differences in composition are associated with equal differences in refractive power. This is shown in the following table (the values are for H°):- Additive relations undoubtedly exist, but many discrepancies occur which may be assigned, as in the case of molecular volumes, to differences in constitution. Atomic refractions may be obtained [PHYSICAL either directly, by investigating the various elements, or indirectly, by considering differences in the molecular refractions of related compounds. The first method needs no explanation. The second method proceeds on the same lines as adopted for atomic volumes. By subtracting the value for CH2, which may be derived from two substances belonging to the same homologous series, from the molecular refraction of methane, See also:CH4, the value of hydrogen is obtained; subtracting this from CH2, the value of carbon is determined. Hyddroxylic oxygen is obtained by subtracting the molecular refractions of acetic acid and acetaldehyde. Similarly, by this method of differences, the atomic refraction of any See also:element may be determined. It is found, however, that the same element has not always the same atomic refraction, the difference being due to the nature of the elements which saturate its valencies. Thus oxygen varies according as whether it is linked to hydrogen (hydroxylic oxygen), to two atoms of carbon (ether oxygen), or to one carbon atom (carbonyl oxygen) ; similarly, carbon varies according as whether it is singly, doubly, or trebly bound to carbon atoms. A table of the atomic refractions and dispersions of the See also:principal elements is here given:- Element. H°. U. Hy. Dispersion Hy-H°. Hydrogen 1.103 I•051 1.139 0.036 Oxygen, hydroxyl . 1.506 1.521 1.525 0.019 ether 1.655 1.683 1.667 0.012 Carbonyl 2.328 2.287 2.414 o.o86 Chlorine 6.014 5.998 6.190 0.176 Bromine 8.863 8.927 9.211 0.348 Iodine 13.808 14.12 14.582 0-774 Carbon (singly bound) 2.365 2.501 2.404 0.039 Double linkage of carbon 1.836 1.707 1.859 0.23 Triple 2.22 2.41 0.19 Nitrogen, singly bound and only to carbon . 2.76 2.95 0.19 Dispersion and Composition.-In the preceding section we have seen that substances possess a definite molecular (or atomic) refraction for light of particular wave-length; the difference between the refractions for any two rays is known as the molecular (or atomic) dispersion. Since molecular refractions are independent of temperature and of the state of aggregation, it follows that molecular dispersions must be also independent of these conditions; and hence quantitative measurements should give an indication as to the chemical composition of substances. This subject has been principally investigated by Bruhl; he found that molecular dispersions of liquids and gases were independent of temperature, and fairly independent of the state of aggregation, but that no simple connexion exists between atomic refractions and dispersions (see preceding table). He also showed how changes in constitution effected dispersions to a far greater extent than they did refractions; thus, while the atomic dispersion of carbon is 0.039, the dispersions due to a double and treble linkage is 0.23 and 0.19 respectively. See also:Colour and Constitution.-In this article a summary of the theories which have been promoted in order to connect the colour of organic compounds with their constitution will be given, and the reader is referred to the article COLOUR for the physical explanation of this property, and to See also:VISION for the physiological and psychological See also:bearings. A clear distinction must be drawn between colour and the property of See also:dyeing; all coloured substances are not dyes, and it is shown in the article DYEING that the property of entering into chemical or physical combination with See also:fibres involves properties other than those essential to colour. At the same See also:time, however, all dyestuffs are coloured substances. A survey of coloured substances led O. N. Witt in 1876 toformulate his " chromophore-auxochrome " theory. On this theory colour is regarded as due to the presence of a " chromophore," and dyeing power to an " auxochrome "; the latter by itself cannot produce colour or dyeing power, but it is only activein the presence of a chromophore, when it intensifies the colour and confers the property of dyeing. The principal chromophores are the See also:azo, -N = N -, azoxy, = N20, nitro, -NO2, nitroso, - NO, and carbonyl, = CO, groups. The azo-group is particularly active, both the aliphatic and aromatic compounds being coloured. The simplest aliphatic compounds, such as diazo-methane, diazo- ethane, and azo-formic acid, are yellow; the diamide of the latter acid is See also:orange-red. Of the aromatic compounds azo-benzene is See also:bright orange-red, and a-azo- See also:naphthalene forms red needles or small See also:steel-See also:blue prisms. The azo- group, however, has little or no colouring effect when present in a Gladstone and Dale. Lorenz and Lorentz. Substance. Temp. Vapour. Liquid. Vapour. Liquid. Water ro° 0.3101 0.3338 0.2068 0.2061 Carbon disulphide . 10° 0.4347 0.4977 0.2898 0.2805 See also:Chloroform ' See also:roe 0.2694 0.3000 0.1796 0.1790 Substance. Mol. Substance. Mol. Diff. for Refract. Refract. CH2. Ethylene chloride C2H4C12 } 20.96 Acetic acid . . 12.93 } 4.49 Ethylidene chloride ( 21.08 Propionic acid . . 17.42 Fumaric acid ( 708g Butyric acid 22.01 4'59 Malefic acid 1 C411404 t 70.29 o-Cresol 32.52 Acetaldehyde . 11'50 } 4'43 m-Cresol C7HBO . . 32.56 Propionaldehyde . . 15.93 p-Cresol 32.57 Butylaldehyde . . 20.52 } 4'59 See also:ring See also:system, such as in cinnolene, phthalazine and tolazone. The nitro group has a very important See also:action mainly on account of the readiness with which It can be introduced into the molecule, but its effect is much less than that of the azo group. The colour produced is generally yellow, which, in accordance with a general rule, is intensified with an increase in the number of groups; compare, for example, mono-, di- and tri-See also:nitrobenzene. The nitroso group is less important. The colour produced is generally of a greenish shade; for example, nitrosobenzene is See also:green when fused or insolution (when crystalline, it is colourless), and dinitrosoresorcin has been employed as a dyestuff under the names " solid green " and " chlorine." The carbonyl group by itself does not produce colour, but when two adjacent groups occur in the molecule, as for example in the a-See also:diketones (such as di-acetyl and benzil), a yellow colour is produced. It also acts as a chromogenic centre when double bonds or ethylenic linkages are present, as in See also:fluorene ketone or fluorenone. A more complex chromophoric group is the triple ethylenic grouping =C > C =, the introduction of which was rendered necessary by the See also:discovery of certain coloured hydrocarbons. As a general rule, hydrocarbons are colourless; the exceptions include the See also:golden yellow acenaphthylene, the red bidiphenylene-ethylene, and the derivatives of fulvene CH : CH > H : CH2, which have been discussed by ~CH J. Thiele (Ber., 1900, 33, p. 666). This grouping is not always colour-producing, since See also:diphenyl is colourless. The most important auxochromes are the hydroxyl (–OH) and amino (–NH2) groups. According to the modern theory of auxochromic action, the introduction of a group into the molecule is accompanied by some See also:strain, and the alteration in colour produced is connected with the magnitude of the strain. The amino group is more powerful than the hydroxyl, and the substituted amino group more powerful still; the repeated substitution of hydroxyl groups sometimes causes an intensification and sometimes a diminution of colour. We may here See also:notice an empirical rule formulated by Nietzski in 1879:—the simplest colouring substances are in the greenish-yellow and yellow, and with increasing molecular weight the colour passes into orange, red, See also:violet, blue and green. This rule, however, is by no means perfect. Examination of the absorption spectra of coloured compounds shows that certain groupings displace the absorption bands in one direction, and other groupings in the other. If the bands be displaced towards the violet, involving a regression through the See also:colours mentioned above, the group is said to be " hypsochromic "; if the See also:reverse occurs the group is " bathochromic." It may be generally inferred that an increase in molecular weight is accompanied by a change in colour in the direction of the violet. Auxochromic groups generally aid one another, i.e. the tint deepens as the number of auxochromes increases. Also the relative position of the auxochrome to the chromophore influences colour, the ortho-position being generally the most powerful. See also:Kauffmann (Ber., 1906, 39, p. 1959) attempted an evaluation of the effects of auxochromic groups by means of the magnetic optical constants. The method is based on the supposition that the magnetic rotation measures the strain produced in the molecule by an auxochrome, and he arranges the groups in the following order: •O•000H3 •OCH5 •NHCOCH3 •NH2 •N(CH3)2 •N(C2Ha)2 -0.260 1.459 .949 3.821 8-587 8.816 The phenomena attending the See also:salt formation of coloured and colouring substances are important. The chromophoric groups are rarely strongly acid or basic; on the other See also:hand, the auxochromes are strongly acid or basic and form salts very readily. Notable differences attend the neutralization of the chromophoric and auxochromic groups. With basic substances, the chromophoric combings tion with a colourless acid is generally attended by a deepening in colour; auxochromic combination, on the other hand, with a lessening. Examples of the first case are found among the colourless acridines and quinoxalines which give coloured salts; of the second case we may notice the colourless hydrochloride and sulphate of the deep yellow o-aminobenzophenone. With acid substances, the combination with " colourless " metals, i.e. metals producing colour-less salts with acids, is attended by colour changes contrary to those given above, auxochromic combination being accompanied by a deepening, and chromophoric by a lessening of the tint. Mention may be made of the phenomenon of halochromism, the name given to the power of colourless or faintly-coloured substances of combining with acids to form highly-coloured substances without the necessary See also:production of a chromophoric group. The researches of Adolf von Baeyer and Villiger, Kehrmann, Kauffmann and others, show that this property is possessed by very many and varied substances. In many cases it may be connected with basic oxygen, and the salt formation is assumed to involve the passage of divalent into tetravalent oxygen. It seems that intermolecular change also occurs, but further See also:research is necessary before a See also:sound theory can be stated. Quinone Theory of Colour.—A theory of colour in opposition to the Witt theory was proposed by Henry See also:Armstrong in 1888 and 1892. This assumed that all coloured substances were derivatives of orthoor para-quinone (see See also:QUINONES), and although at the time of itspromotion little See also:practical proof was given, yet the theory found wide See also:acceptance on account of the researches of many other chemists. It follows on this theory that all coloured substances contain either of the groupings 'CD- or Cl- , the former being a para-quinonoid, the latter an ortho-quinonoid. While very many coloured substances must obviously contain this grouping, yet in many cases it is necessary to assume a simple intermolecularchange, while in others a more complex rearrangement of bonds is necessary. Quinone, which is light yellow in colour, is the simplest coloured substance on this theory. Hydrocarbons of similar structure have been prepared by Thiele, for example, the orange-yellow tetraphenyl-para-xylylene, which is obtained by boiling the bromide See also:C6H4[CBr(See also:C6H5)2]2 with benzene and molecular See also:silver. The quinonoid structure of many coloured compounds has been proved experimentally, as, for example, by See also:Hewitt for the benzene-azo-phenols, and Hantzsch for triaminotriphenyl methane and See also:acridine derivatives; .but, at the same time, many substances cannot be so explained. A notable example is provided by the phthaleins, which result by the condensation of See also:phthalic anhydride with phenols. In the free state these substances are colourless, and were assumed to have the formula shown in 1. See also:Solution in dilute See also:alkali was supposed to be accompanied by the rupture of the lactone ring with the formation of the quinoncid salt shown in 2. Additional information and CommentsThere are no comments yet for this article.
» Add information or comments to this article.
Please link directly to this article:
Highlight the code below, right click, and select "copy." Then paste it into your website, email, or other HTML. Site content, images, and layout Copyright © 2006 - Net Industries, worldwide. |
|
|
[back] CH3CO(4) |
[next] CH4 |