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yueya2545065

铜虫 (初入文坛)

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hpyou

铁杆木虫 (小有名气)

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yueya2545065(金币+2,VIP+0):不太详细 但还要谢谢你
分子式: H2P2O7
CAS号:

性质:无色黏稠液体,久置生成结晶。密度2.04g/cm3(25℃)。熔点61℃。用水稀释易变为正磷酸。易溶于水,其水溶液有强酸性。焦磷酸根遇银盐得白色焦磷酸银沉淀。由正磷酸热至210℃,失水而成焦磷酸。纯焦磷酸可由磷酸氢钠加热得焦磷酸钠,将其溶解,转化成焦磷酸铅沉淀,再通入硫化氢,过滤将滤液真空低温浓缩即得。常用作催化剂,制有机磷酸酯等。
2楼2008-09-26 10:38:12
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zhangquee

至尊木虫 (文坛精英)

爱花不采花,潇洒不乱洒!

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CCD2004上信息

Diphosphoric acid
Synonym(s): Pyrophosphoric acid. Heptaoxodiphosphoric(V,V) acid. P5OP5 acid. Tetrahydrogen -oxo-hexaoxophosphate. -Oxo-hexaoxodiphosphoric acid
CRC Number: HTV84-C
CAS Registry Number: 2466-09-3
(HO)2P(O)OP(O)(OH)2

Molecular Formula: H4O7P2
Molecular Weight: 177.975
Accurate Mass: 177.943229
Percentage Composition: H 2.27%; O 62.93%; P 34.81%
Source/Synthesis: Synth. from H3PO4 + P4O10, or by heating H3PO4 at 100-200
Biological Use/Importance: Present in normal plasma and other biological fluids, bone and teeth. Abnormality in metabolism leads to hypophosphatasia - an inherited bone disease. Many organic derivs. are also biologically important being involved in biological phosphorylations
Dissociation Constant: pKa1 0.8; pKa2 1.8; pKa3 6.04; pKa4 9 (25) pKa3 5.98; pKa4 8.3 pKa3 5.76; pKa4 8.04

RCB_CT,229949Variant: I-form
CRC Number: JNT71-S
Molecular Formula: H4O7P2
Molecular Weight: 177.975
Accurate Mass: 177.943229
Percentage Composition: H 2.27%; O 62.93%; P 34.81%
Physical Description: Orthorhombic, colourless cryst. Metastable
Melting Point: Mp 54.3
Other Data: Converts into form II when heated in sealed tube at 50
RCB_CT,229950Variant: II-form
CRC Number: HTV92-D
Molecular Formula: H4O7P2
Molecular Weight: 177.975
Accurate Mass: 177.943229
Percentage Composition: H 2.27%; O 62.93%; P 34.81%
Physical Description: Orthorhombic, colourless cryst
Melting Point: Mp 71.5
Other Data: Stable at r.t.
RCB_CT,229951Derivative: Tetra-NH4 salt
see Ammonium diphosphate ((NH4)4(P2O7)), HTW32-Q
CRC Number: HTV93-E
RCB_CT,229952Derivative: Tetra-Li salt
see Lithium diphosphate (Li4(P2O7)), HTW35-T
CRC Number: JNT72-T
RCB_CT,229953Derivative: Tetra-Na salt
see Sodium diphosphate (Na4(P2O7)), HTW34-S
CRC Number: HTL80-A
RCB_CT,229954Derivative: Tetra-K salt
see Potassium diphosphate (K4(P2O7)), HTW33-R
CRC Number: HTL64-Y
References:
Inorg. Synth., 1950, 3, 96 (synth, props)
Wakefield, Z. et al., J. Agric. Food Chem., 1962, 10, 344 (props)
Gmelin Handbook Inorg. Chem., Syst. No. 16, 1965, 224
Russell, R.G.G. et al., Br. J. Hosp. Med., 1975, 14, 299 (metab, physiol)
Russell, R.G.G. et al., Clin. Orthop. Relat. Res., 1975, 108, 241 (rev, biol importance)
Fluck, E. et al., Pure Appl. Chem., 1975, 44, 373 (pe)
Geraldes, C.F.G.C. et al., J. Inorg. Biochem., 1989, 37, 213 (P-31 nmr)
一笑而过~
3楼2008-09-26 10:55:52
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