SOLUBLE COMPLEXES IN THE SYSTEMS DICALCIUM PHOSPHATE DIHYDRATE OR DIMAGNESIUM PHOSPHATE TRIHYDRATE EQUILIBRATED WITH AQUEOUS SALT SOLUTIONS

[摘要] Dicalciumphosphatedihydrate(CaHPO4∙2H2O)(DCPD)ordimagnesiumphosphatetrihydrate(MgHPO4∙3H2O)(DMPT)wasequilibratedwithwateroraqueoussolutionsofCaCl2,CaSO4,MgCl2,MgSO4,KClorK2SO4at25 ± 1 Cfor24 hr.ValuesofpCa + pHPO4andpMg + pHPO4correctedforcomplexformation,usingdissociationconstantspublishedforCaHPO4,MgHPO4,CaSO4andMgSO4solublecomplexes,werecalculated.TheaveragecorrectedvalueofpCa + pHPO4 = 6.68 ± 0.03,calculatedforthesystemsinwhichDCPDwasequilibratedwithwateroraqueousCaCl2,CaSO4,KClorK2SO4,waslargerthanpCa + pHPO4 = pKDCPD = 0.36at25 Ccalculatedassuminganabsenceofsolublecomplexes.However,itshowedexcellentagreementwithpKDCPD = 6.66 ± 0.02at37.5 CcalculatedassumingCaH2PO4+andCaHPO4complexestobepresent.TheaveragecorrectedvalueofpMg + pHPO4 = 5.82 ± 0.01,calculatedforthesystemsinwhichDMPTwasequilibratedwithwateroraqueousMgCl2,MgSO4,KClorK2SO4showedexcellentagreementwithpMg + ...

[学科分类] 农业科学（综合）