缩合磷酸盐的水解作用：一,焦磷酸钠和磷酸
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1liλb1faannuzsrcsrciripptt recæeivedd J a nuary 1I S3, 19856. Contributlion from the Deep户airrt!mmen!t off Clhzeemttliissttrryy, Otnttlario Research Fouzrnnddαattiioon,， Toron!to 5, Ontario.
The phosphoric acids are very viscous, so that equilibria are attained very slowlyy;; the end result off cooling is an oil in the range 72 to 82y%0 PPz20OSj,, a gum in the range 82 to 86y%o PP 2P0zS0, 5an, d a brittle glass at higher PPz2O05s concentrations. These acids are merely members off a continuous series off amorphous condensed phosphoric acid mixtures which extends froomm orthophosphoric acid to pure phosphorus pentoxide (388)).. These mixtures are hygroscopic and hydrolyze upon standing unJless stored in tighttJly closed pyrex containers.
I NTRI IOODDUUCTIIOONN
The composition off the strong phosphoric acids,** i.e. acids containing more
than 72..44%y0 by weight off phosphorus pentoxide , the PP ?2005S wk.baidu.comontent off pure
7866
CANNAADDlIANN ]JOUüRRNALL OF C CH HEE孔MlIISSTTRRYY.. VOL. 34 , 195%6
previously in the literature. Some of these have since then been positively identified , e.g. the tetrapolyphosphoric acidd, H6SP4401133 , while for others there is enough evidence to date to make their existence highly improbable, e.g. the metaphosphoric acid monomer, HHPPO0Z3•. Finally, some of the acids listed by the above-mentioned authors, which at the time represented merely theoretical combinations of phosphorus pentoxide and water, have during the present study been positively identified as far as this is possible by paper chromatography, and their relative concentrations in several mixtures accurately established , e.g. "hexerohexapphhoosspphhoorriicc"" acid , Hs8P6S0O1 l日9， ,better klrnnoown today as hexapolyphosphoric acid. The same authors checked the analytical methods of Gerber and Miles (119)) against those of Britske and Dragunov (66)) and found an increasing divergence when acids of high phosphorus pernlttoxide content were being analyzed. This they considered as evidence that polyphosphoric acids may be present in the strong phosphoric acids.
1It has been shown by means off paper chroommaatotoggrarpahp!h.y that by~ m, ixsing orthophosphoric acid with phosphorus pentoxide at different ratios, and heating the mixture at 3500。°C巳，., we obtain a mixture containing on~ll)l'\l,inear condensed polyphosphoric acids. No0 cyclic ones 飞w飞rere foundd.. Branched acids, if present, would not be detected , since any ion--mn~oolelceucluelseswith branching are expected to hydrolyze immediately upon disssoolluuttiioon~l (400)).. A certain characteristic equilibrium mixture exists for ever?y; given ratio off water to phosphorus pentoxide.
orthophosphoric acidd, is a subject off considerable interest which has been repeatedly investigated by wet analytical methods. Difficulties in these methods, however, have set a decided limitation on the qualitative and quantitative conclusions possible. A study off this subject by filter-paper chromn~aatotoggrarpahpyhywas ~u I~1dnedrtearkteank,e nth,erefore , in order to obtain further and more speecciif且ic information about compositions having a mole ratio off water to phosphorus pentoxide between 3.6 and 1..22..
Bell (33)) went a step further by recognizing that tripolyphosphoric acid is present and interferes in some procedures for pyrophosphate determinatioonn.. By using an analytical method previously developed by the same author (55)),, he was able to show the presence of ortho- , pyro- , and tripolyphosphoriicc acids in several of the strong phosphoric acid mixtures, and of "the polymer of metaphosphoric acid commonly known as hexametaphosphoric acid"".. A1n1 "unidentiiffiieedd"" acidd, indicated by ddiif汀ference,， was also present between 78 and 88% phosphorus pentoxide.
The existence off strong phosphoric acids has been known for many years. Durginn, Lum, and Malowan (1144)) give a list off several such acids reported
By ANNA-LrrSA HUHTI AND PHOEBUS A. GARTAGANIS
ABSTRACT The c~ommppoosisittiion of the strong phosphoric acids was stluldied in the range 68.8 to 86.:33y%0 phosphorluls pentoxide by weigghht.. Improved filter--ppaappeerr chromatographhyy made possible the ql~la~natnittaittiavtei vdeetteerrm口liinnattiioon of the nine lower members of the seriess, and occcaassioi ona~lilya l lluI~pP to the twelfth member. It was fOoullnd that when the strong phosphoric acids are prepared by heating at :3350°oC., a dynamic eqlulilibrilulm between the component acicdlss is set up 飞w，vhiich persists when the mixtures are cooled to room temperaturee.. O01nl1y1l~inear condensed polyphosphoric aacids were present in the range sttu~d~ieddi.eTd h. e comlnposition corresponding to 100% orthophosphoriicc acid contains abolult 6 mole per cent each of pyrophhoosspphhoorriicc acidd' and' "freeee waatteerr"".. }A\S5 the mole ratio of water to phosphorluls pentoxide decreases, the number of component acidss increases. Orthophosphoricc acid is present to an appreciable exsttent in the stronger phosphoric acids. "Hexametaphosphoric acid" is I1l1oott a separate chemical entity, blult a mixture of higher linliear polyphosphoric acids.
Can. J. Chem. Downloaded from www.nrcresearchpress.com by 107.178.200.180 on 04/22/15 For personal use only.
THE COMPOSITION OF THE STRONG PHOSPHORIC ACIIDSl1
**AA comnmzercial termm, a high degree off ionizatioon not necessarily iimmp户lliieed..
7855
Can. J. Chem. Downloaded from www.nrcresearchpress.com by 107.178.200.180 on 04/22/15 For personal use only.
The phosphoric acids are very viscous, so that equilibria are attained very slowlyy;; the end result off cooling is an oil in the range 72 to 82y%0 PPz20OSj,, a gum in the range 82 to 86y%o PP 2P0zS0, 5an, d a brittle glass at higher PPz2O05s concentrations. These acids are merely members off a continuous series off amorphous condensed phosphoric acid mixtures which extends froomm orthophosphoric acid to pure phosphorus pentoxide (388)).. These mixtures are hygroscopic and hydrolyze upon standing unJless stored in tighttJly closed pyrex containers.
I NTRI IOODDUUCTIIOONN
The composition off the strong phosphoric acids,** i.e. acids containing more
than 72..44%y0 by weight off phosphorus pentoxide , the PP ?2005S wk.baidu.comontent off pure
7866
CANNAADDlIANN ]JOUüRRNALL OF C CH HEE孔MlIISSTTRRYY.. VOL. 34 , 195%6
previously in the literature. Some of these have since then been positively identified , e.g. the tetrapolyphosphoric acidd, H6SP4401133 , while for others there is enough evidence to date to make their existence highly improbable, e.g. the metaphosphoric acid monomer, HHPPO0Z3•. Finally, some of the acids listed by the above-mentioned authors, which at the time represented merely theoretical combinations of phosphorus pentoxide and water, have during the present study been positively identified as far as this is possible by paper chromatography, and their relative concentrations in several mixtures accurately established , e.g. "hexerohexapphhoosspphhoorriicc"" acid , Hs8P6S0O1 l日9， ,better klrnnoown today as hexapolyphosphoric acid. The same authors checked the analytical methods of Gerber and Miles (119)) against those of Britske and Dragunov (66)) and found an increasing divergence when acids of high phosphorus pernlttoxide content were being analyzed. This they considered as evidence that polyphosphoric acids may be present in the strong phosphoric acids.
1It has been shown by means off paper chroommaatotoggrarpahp!h.y that by~ m, ixsing orthophosphoric acid with phosphorus pentoxide at different ratios, and heating the mixture at 3500。°C巳，., we obtain a mixture containing on~ll)l'\l,inear condensed polyphosphoric acids. No0 cyclic ones 飞w飞rere foundd.. Branched acids, if present, would not be detected , since any ion--mn~oolelceucluelseswith branching are expected to hydrolyze immediately upon disssoolluuttiioon~l (400)).. A certain characteristic equilibrium mixture exists for ever?y; given ratio off water to phosphorus pentoxide.
orthophosphoric acidd, is a subject off considerable interest which has been repeatedly investigated by wet analytical methods. Difficulties in these methods, however, have set a decided limitation on the qualitative and quantitative conclusions possible. A study off this subject by filter-paper chromn~aatotoggrarpahpyhywas ~u I~1dnedrtearkteank,e nth,erefore , in order to obtain further and more speecciif且ic information about compositions having a mole ratio off water to phosphorus pentoxide between 3.6 and 1..22..
Bell (33)) went a step further by recognizing that tripolyphosphoric acid is present and interferes in some procedures for pyrophosphate determinatioonn.. By using an analytical method previously developed by the same author (55)),, he was able to show the presence of ortho- , pyro- , and tripolyphosphoriicc acids in several of the strong phosphoric acid mixtures, and of "the polymer of metaphosphoric acid commonly known as hexametaphosphoric acid"".. A1n1 "unidentiiffiieedd"" acidd, indicated by ddiif汀ference,， was also present between 78 and 88% phosphorus pentoxide.
The existence off strong phosphoric acids has been known for many years. Durginn, Lum, and Malowan (1144)) give a list off several such acids reported
By ANNA-LrrSA HUHTI AND PHOEBUS A. GARTAGANIS
ABSTRACT The c~ommppoosisittiion of the strong phosphoric acids was stluldied in the range 68.8 to 86.:33y%0 phosphorluls pentoxide by weigghht.. Improved filter--ppaappeerr chromatographhyy made possible the ql~la~natnittaittiavtei vdeetteerrm口liinnattiioon of the nine lower members of the seriess, and occcaassioi ona~lilya l lluI~pP to the twelfth member. It was fOoullnd that when the strong phosphoric acids are prepared by heating at :3350°oC., a dynamic eqlulilibrilulm between the component acicdlss is set up 飞w，vhiich persists when the mixtures are cooled to room temperaturee.. O01nl1y1l~inear condensed polyphosphoric aacids were present in the range sttu~d~ieddi.eTd h. e comlnposition corresponding to 100% orthophosphoriicc acid contains abolult 6 mole per cent each of pyrophhoosspphhoorriicc acidd' and' "freeee waatteerr"".. }A\S5 the mole ratio of water to phosphorluls pentoxide decreases, the number of component acidss increases. Orthophosphoricc acid is present to an appreciable exsttent in the stronger phosphoric acids. "Hexametaphosphoric acid" is I1l1oott a separate chemical entity, blult a mixture of higher linliear polyphosphoric acids.
Can. J. Chem. Downloaded from www.nrcresearchpress.com by 107.178.200.180 on 04/22/15 For personal use only.
THE COMPOSITION OF THE STRONG PHOSPHORIC ACIIDSl1
**AA comnmzercial termm, a high degree off ionizatioon not necessarily iimmp户lliieed..
7855
Can. J. Chem. Downloaded from www.nrcresearchpress.com by 107.178.200.180 on 04/22/15 For personal use only.